    <!--


    var pi = 3.14159265358979;


    /* Ellipsoid model constants (actual values here are for WGS84) */

    var sm_a = 6378137.0;

    var sm_b = 6356752.314;

    var sm_EccSquared = 6.69437999013e-03;


    var UTMScaleFactor = 0.9996;


    /*

    * DegToRad

    *

    * Converts degrees to radians.

    *

    */

    function DegToRad (deg)

    {

        return (deg / 180.0 * pi)

    }


    /*

    * RadToDeg

    *

    * Converts radians to degrees.

    *

    */

    function RadToDeg (rad)

    {

        return (rad / pi * 180.0)

    }


    /*

    * ArcLengthOfMeridian

    *

    * Computes the ellipsoidal distance from the equator to a point at a

    * given latitude.

    *

    * Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,

    * GPS: Theory and Practice, 3rd ed.  New York: Springer-Verlag Wien, 1994.

    *

    * Inputs:

    *     phi - Latitude of the point, in radians.

    *

    * Globals:

    *     sm_a - Ellipsoid model major axis.

    *     sm_b - Ellipsoid model minor axis.

    *

    * Returns:

    *     The ellipsoidal distance of the point from the equator, in meters.

    *

    */

    function ArcLengthOfMeridian (phi)

    {

        var alpha, beta, gamma, delta, epsilon, n;

        var result;


        /* Precalculate n */

        n = (sm_a - sm_b) / (sm_a + sm_b);


        /* Precalculate alpha */

        alpha = ((sm_a + sm_b) / 2.0)

           * (1.0 + (Math.pow (n, 2.0) / 4.0) + (Math.pow (n, 4.0) / 64.0));


        /* Precalculate beta */

        beta = (-3.0 * n / 2.0) + (9.0 * Math.pow (n, 3.0) / 16.0)

           + (-3.0 * Math.pow (n, 5.0) / 32.0);


        /* Precalculate gamma */

        gamma = (15.0 * Math.pow (n, 2.0) / 16.0)

            + (-15.0 * Math.pow (n, 4.0) / 32.0);

    
        /* Precalculate delta */

        delta = (-35.0 * Math.pow (n, 3.0) / 48.0)

            + (105.0 * Math.pow (n, 5.0) / 256.0);

    
        /* Precalculate epsilon */

        epsilon = (315.0 * Math.pow (n, 4.0) / 512.0);

    
    /* Now calculate the sum of the series and return */

    result = alpha

        * (phi + (beta * Math.sin (2.0 * phi))

            + (gamma * Math.sin (4.0 * phi))

            + (delta * Math.sin (6.0 * phi))

            + (epsilon * Math.sin (8.0 * phi)));


    return result;

    }


    /*

    * UTMCentralMeridian

    *

    * Determines the central meridian for the given UTM zone.

    *

    * Inputs:

    *     zone - An integer value designating the UTM zone, range [1,60].

    *

    * Returns:

    *   The central meridian for the given UTM zone, in radians, or zero

    *   if the UTM zone parameter is outside the range [1,60].

    *   Range of the central meridian is the radian equivalent of [-177,+177].

    *

    */

    function UTMCentralMeridian (zone)

    {

        var cmeridian;


        cmeridian = DegToRad (-183.0 + (zone * 6.0));

    
        return cmeridian;

    }


    /*

    * FootpointLatitude

    *

    * Computes the footpoint latitude for use in converting transverse

    * Mercator coordinates to ellipsoidal coordinates.

    *

    * Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,

    *   GPS: Theory and Practice, 3rd ed.  New York: Springer-Verlag Wien, 1994.

    *

    * Inputs:

    *   y - The UTM northing coordinate, in meters.

    *

    * Returns:

    *   The footpoint latitude, in radians.

    *

    */

    function FootpointLatitude (y)

    {

        var y_, alpha_, beta_, gamma_, delta_, epsilon_, n;

        var result;

        
        /* Precalculate n (Eq. 10.18) */

        n = (sm_a - sm_b) / (sm_a + sm_b);

        	
        /* Precalculate alpha_ (Eq. 10.22) */

        /* (Same as alpha in Eq. 10.17) */

        alpha_ = ((sm_a + sm_b) / 2.0)

            * (1 + (Math.pow (n, 2.0) / 4) + (Math.pow (n, 4.0) / 64));

        
        /* Precalculate y_ (Eq. 10.23) */

        y_ = y / alpha_;

        
        /* Precalculate beta_ (Eq. 10.22) */

        beta_ = (3.0 * n / 2.0) + (-27.0 * Math.pow (n, 3.0) / 32.0)

            + (269.0 * Math.pow (n, 5.0) / 512.0);

        
        /* Precalculate gamma_ (Eq. 10.22) */

        gamma_ = (21.0 * Math.pow (n, 2.0) / 16.0)

            + (-55.0 * Math.pow (n, 4.0) / 32.0);

        	
        /* Precalculate delta_ (Eq. 10.22) */

        delta_ = (151.0 * Math.pow (n, 3.0) / 96.0)

            + (-417.0 * Math.pow (n, 5.0) / 128.0);

        	
        /* Precalculate epsilon_ (Eq. 10.22) */

        epsilon_ = (1097.0 * Math.pow (n, 4.0) / 512.0);

        	
        /* Now calculate the sum of the series (Eq. 10.21) */

        result = y_ + (beta_ * Math.sin (2.0 * y_))

            + (gamma_ * Math.sin (4.0 * y_))

            + (delta_ * Math.sin (6.0 * y_))

            + (epsilon_ * Math.sin (8.0 * y_));

        
        return result;

    }


    /*

    * MapLatLonToXY

    *

    * Converts a latitude/longitude pair to x and y coordinates in the

    * Transverse Mercator projection.  Note that Transverse Mercator is not

    * the same as UTM; a scale factor is required to convert between them.

    *

    * Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,

    * GPS: Theory and Practice, 3rd ed.  New York: Springer-Verlag Wien, 1994.

    *

    * Inputs:

    *    phi - Latitude of the point, in radians.

    *    lambda - Longitude of the point, in radians.

    *    lambda0 - Longitude of the central meridian to be used, in radians.

    *

    * Outputs:

    *    xy - A 2-element array containing the x and y coordinates

    *         of the computed point.

    *

    * Returns:

    *    The function does not return a value.

    *

    */

    function MapLatLonToXY (phi, lambda, lambda0, xy)

    {

        var N, nu2, ep2, t, t2, l;

        var l3coef, l4coef, l5coef, l6coef, l7coef, l8coef;

        var tmp;


        /* Precalculate ep2 */

        ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0)) / Math.pow (sm_b, 2.0);

    
        /* Precalculate nu2 */

        nu2 = ep2 * Math.pow (Math.cos (phi), 2.0);

    
        /* Precalculate N */

        N = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 + nu2));

    
        /* Precalculate t */

        t = Math.tan (phi);

        t2 = t * t;

        tmp = (t2 * t2 * t2) - Math.pow (t, 6.0);


        /* Precalculate l */

        l = lambda - lambda0;

    
        /* Precalculate coefficients for l**n in the equations below

           so a normal human being can read the expressions for easting

           and northing

           -- l**1 and l**2 have coefficients of 1.0 */

        l3coef = 1.0 - t2 + nu2;

    
        l4coef = 5.0 - t2 + 9 * nu2 + 4.0 * (nu2 * nu2);

    
        l5coef = 5.0 - 18.0 * t2 + (t2 * t2) + 14.0 * nu2

            - 58.0 * t2 * nu2;

    
        l6coef = 61.0 - 58.0 * t2 + (t2 * t2) + 270.0 * nu2

            - 330.0 * t2 * nu2;

    
        l7coef = 61.0 - 479.0 * t2 + 179.0 * (t2 * t2) - (t2 * t2 * t2);

    
        l8coef = 1385.0 - 3111.0 * t2 + 543.0 * (t2 * t2) - (t2 * t2 * t2);

    
        /* Calculate easting (x) */

        xy[0] = N * Math.cos (phi) * l

            + (N / 6.0 * Math.pow (Math.cos (phi), 3.0) * l3coef * Math.pow (l, 3.0))

            + (N / 120.0 * Math.pow (Math.cos (phi), 5.0) * l5coef * Math.pow (l, 5.0))

            + (N / 5040.0 * Math.pow (Math.cos (phi), 7.0) * l7coef * Math.pow (l, 7.0));

    
        /* Calculate northing (y) */

        xy[1] = ArcLengthOfMeridian (phi)

            + (t / 2.0 * N * Math.pow (Math.cos (phi), 2.0) * Math.pow (l, 2.0))

            + (t / 24.0 * N * Math.pow (Math.cos (phi), 4.0) * l4coef * Math.pow (l, 4.0))

            + (t / 720.0 * N * Math.pow (Math.cos (phi), 6.0) * l6coef * Math.pow (l, 6.0))

            + (t / 40320.0 * N * Math.pow (Math.cos (phi), 8.0) * l8coef * Math.pow (l, 8.0));

    
        return;

    }

    
    /*

    * MapXYToLatLon

    *

    * Converts x and y coordinates in the Transverse Mercator projection to

    * a latitude/longitude pair.  Note that Transverse Mercator is not

    * the same as UTM; a scale factor is required to convert between them.

    *

    * Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,

    *   GPS: Theory and Practice, 3rd ed.  New York: Springer-Verlag Wien, 1994.

    *

    * Inputs:

    *   x - The easting of the point, in meters.

    *   y - The northing of the point, in meters.

    *   lambda0 - Longitude of the central meridian to be used, in radians.

    *

    * Outputs:

    *   philambda - A 2-element containing the latitude and longitude

    *               in radians.

    *

    * Returns:

    *   The function does not return a value.

    *

    * Remarks:

    *   The local variables Nf, nuf2, tf, and tf2 serve the same purpose as

    *   N, nu2, t, and t2 in MapLatLonToXY, but they are computed with respect

    *   to the footpoint latitude phif.

    *

    *   x1frac, x2frac, x2poly, x3poly, etc. are to enhance readability and

    *   to optimize computations.

    *

    */

    function MapXYToLatLon (x, y, lambda0, philambda)

    {

        var phif, Nf, Nfpow, nuf2, ep2, tf, tf2, tf4, cf;

        var x1frac, x2frac, x3frac, x4frac, x5frac, x6frac, x7frac, x8frac;

        var x2poly, x3poly, x4poly, x5poly, x6poly, x7poly, x8poly;

    	
        /* Get the value of phif, the footpoint latitude. */

        phif = FootpointLatitude (y);

        	
        /* Precalculate ep2 */

        ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0))

              / Math.pow (sm_b, 2.0);

        	
        /* Precalculate cos (phif) */

        cf = Math.cos (phif);

        	
        /* Precalculate nuf2 */

        nuf2 = ep2 * Math.pow (cf, 2.0);

        	
        /* Precalculate Nf and initialize Nfpow */

        Nf = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 + nuf2));

        Nfpow = Nf;

        	
        /* Precalculate tf */

        tf = Math.tan (phif);

        tf2 = tf * tf;

        tf4 = tf2 * tf2;

        
        /* Precalculate fractional coefficients for x**n in the equations

           below to simplify the expressions for latitude and longitude. */

        x1frac = 1.0 / (Nfpow * cf);

        
        Nfpow *= Nf;   /* now equals Nf**2) */

        x2frac = tf / (2.0 * Nfpow);

        
        Nfpow *= Nf;   /* now equals Nf**3) */

        x3frac = 1.0 / (6.0 * Nfpow * cf);

        
        Nfpow *= Nf;   /* now equals Nf**4) */

        x4frac = tf / (24.0 * Nfpow);

        
        Nfpow *= Nf;   /* now equals Nf**5) */

        x5frac = 1.0 / (120.0 * Nfpow * cf);

        
        Nfpow *= Nf;   /* now equals Nf**6) */

        x6frac = tf / (720.0 * Nfpow);

        
        Nfpow *= Nf;   /* now equals Nf**7) */

        x7frac = 1.0 / (5040.0 * Nfpow * cf);

        
        Nfpow *= Nf;   /* now equals Nf**8) */

        x8frac = tf / (40320.0 * Nfpow);

        
        /* Precalculate polynomial coefficients for x**n.

           -- x**1 does not have a polynomial coefficient. */

        x2poly = -1.0 - nuf2;

        
        x3poly = -1.0 - 2 * tf2 - nuf2;

        
        x4poly = 5.0 + 3.0 * tf2 + 6.0 * nuf2 - 6.0 * tf2 * nuf2

        	- 3.0 * (nuf2 *nuf2) - 9.0 * tf2 * (nuf2 * nuf2);

        
        x5poly = 5.0 + 28.0 * tf2 + 24.0 * tf4 + 6.0 * nuf2 + 8.0 * tf2 * nuf2;

        
        x6poly = -61.0 - 90.0 * tf2 - 45.0 * tf4 - 107.0 * nuf2

        	+ 162.0 * tf2 * nuf2;

        
        x7poly = -61.0 - 662.0 * tf2 - 1320.0 * tf4 - 720.0 * (tf4 * tf2);

        
        x8poly = 1385.0 + 3633.0 * tf2 + 4095.0 * tf4 + 1575 * (tf4 * tf2);

        	
        /* Calculate latitude */

        philambda[0] = phif + x2frac * x2poly * (x * x)

        	+ x4frac * x4poly * Math.pow (x, 4.0)

        	+ x6frac * x6poly * Math.pow (x, 6.0)

        	+ x8frac * x8poly * Math.pow (x, 8.0);

        	
        /* Calculate longitude */

        philambda[1] = lambda0 + x1frac * x

        	+ x3frac * x3poly * Math.pow (x, 3.0)

        	+ x5frac * x5poly * Math.pow (x, 5.0)

        	+ x7frac * x7poly * Math.pow (x, 7.0);

        	
        return;

    }


    /*

    * LatLonToUTMXY

    *

    * Converts a latitude/longitude pair to x and y coordinates in the

    * Universal Transverse Mercator projection.

    *

    * Inputs:

    *   lat - Latitude of the point, in radians.

    *   lon - Longitude of the point, in radians.

    *   zone - UTM zone to be used for calculating values for x and y.

    *          If zone is less than 1 or greater than 60, the routine

    *          will determine the appropriate zone from the value of lon.

    *

    * Outputs:

    *   xy - A 2-element array where the UTM x and y values will be stored.

    *

    * Returns:

    *   The UTM zone used for calculating the values of x and y.

    *

    */

    function LatLonToUTMXY (lat, lon, zone, xy)

    {

        MapLatLonToXY (lat, lon, UTMCentralMeridian (zone), xy);


        /* Adjust easting and northing for UTM system. */

        xy[0] = xy[0] * UTMScaleFactor + 500000.0;

        xy[1] = xy[1] * UTMScaleFactor;

        if (xy[1] < 0.0)

            xy[1] = xy[1] + 10000000.0;


        return zone;

    }

    
    /*

    * UTMXYToLatLon

    *

    * Converts x and y coordinates in the Universal Transverse Mercator

    * projection to a latitude/longitude pair.

    *

    * Inputs:

    *	x - The easting of the point, in meters.

    *	y - The northing of the point, in meters.

    *	zone - The UTM zone in which the point lies.

    *	southhemi - True if the point is in the southern hemisphere;

    *               false otherwise.

    *

    * Outputs:

    *	latlon - A 2-element array containing the latitude and

    *            longitude of the point, in radians.

    *

    * Returns:

    *	The function does not return a value.

    *

    */

    function UTMXYToLatLon (x, y, zone, southhemi, latlon)

    {

        var cmeridian;

        	
        x -= 500000.0;

        x /= UTMScaleFactor;

        	
        /* If in southern hemisphere, adjust y accordingly. */

        if (southhemi)

        y -= 10000000.0;

        		
        y /= UTMScaleFactor;

        
        cmeridian = UTMCentralMeridian (zone);

        MapXYToLatLon (x, y, cmeridian, latlon);

        	
        return;

    }

    
//**********************************

function roundNumber(rnum, rlength){

  var newnumber = Math.round(rnum*Math.pow(10,rlength))/Math.pow(10,rlength);

  return newnumber; 

}


    /*********************************************************************************************************

    * btnToUTM_OnClick

    *

    * Called when the btnToUTM button is clicked.

    *

    */

    function btnToUTM_OnClick ()

    {

        var xy = new Array(2);

        
        if (isNaN (parseFloat (document.frmConverter.txtLongitude.value))) {

            alert ("Please enter a valid longitude in the lon field.");

            return false;

        }


        lon = parseFloat (document.frmConverter.txtLongitude.value);


        if ((lon < -180.0) || (180.0 <= lon)) {

            alert ("The longitude you entered is out of range.  " +

                   "Please enter a number in the range [-180, 180).");

            return false;

        }


        if (isNaN (parseFloat (document.frmConverter.txtLatitude.value))) {

            alert ("Please enter a valid latitude in the lat field.");

            return false;

        }


        lat = parseFloat (document.frmConverter.txtLatitude.value);


        if ((lat < -90.0) || (90.0 < lat)) {

            alert ("The latitude you entered is out of range.  " +

                   "Please enter a number in the range [-90, 90].");

            return false;

        }


        // Compute the UTM zone.

        zone = Math.floor ((lon + 180.0) / 6) + 1;


        zone = LatLonToUTMXY (DegToRad (lat), DegToRad (lon), zone, xy);


        /* Set the output controls.  */

        document.frmConverter.txtX.value = roundNumber(xy[0],2);

        document.frmConverter.txtY.value = roundNumber(xy[1],2);

        document.frmConverter.txtZone.value = zone;

        if (lat < 0)

            // Set the S button.

          //////  document.frmConverter.rbtnHemisphere[1].checked = true;

            document.frmConverter.rbtnHemisphere.value = 'Sur';

        else

            // Set the N button.

            ////////document.frmConverter.rbtnHemisphere[0].checked = true;

            document.frmConverter.rbtnHemisphere.value = 'Norte';

        
        return true;

    }


    /*

    * btnToGeographic_OnClick

    *

    * Called when the btnToGeographic button is clicked.

    *

    */

    function btnToGeographic_OnClick ()

    {                                  

        latlon = new Array(2);

        var x, y, zone, southhemi;

        
        if (isNaN (parseFloat (document.frmConverter.txtX.value))) {

            alert ("Please enter a valid easting in the x field.");

            return false;

        }


        x = parseFloat (document.frmConverter.txtX.value);


        if (isNaN (parseFloat (document.frmConverter.txtY.value))) {

            alert ("Please enter a valid northing in the y field.");

            return false;

        }


        y = parseFloat (document.frmConverter.txtY.value);


        if (isNaN (parseInt (document.frmConverter.txtZone.value))) {

            alert ("Please enter a valid UTM zone in the zone field.");

            return false;

        }


        zone = parseFloat (document.frmConverter.txtZone.value);


        if ((zone < 1) || (60 < zone)) {

            alert ("The UTM zone you entered is out of range.  " +

                   "Please enter a number in the range [1, 60].");

            return false;

        }

        
        if (document.frmConverter.rbtnHemisphere[1].checked == true)

            southhemi = true;

        else

            southhemi = false;


        UTMXYToLatLon (x, y, zone, southhemi, latlon);

        
        document.frmConverter.txtLongitude.value = RadToDeg (latlon[1]);

        document.frmConverter.txtLatitude.value = RadToDeg (latlon[0]);


        return true;

    }


    //    -->