Google Maps Api Coodrinates

gistfile1.js

$("#SomeIDOfATextBox").val("Some value");
//Can be replaced by:
document.getElementById('SomeIDOfATextBox').value = "Some value";

gistfile2.js

var map;
function initialize() {
 
   if (GBrowserIsCompatible()) //a check to make sure the browser is compatible for GEmaps.
   {
     map = new GMap2(document.getElementById("map_canvas")); //assign the div to map var
     map.setCenter(new GLatLng(18, -77.4), 13); //centering the location
     map.setUIToDefault(); //setting the default location to the center.
 
    //The GE event for clicking the map.
    GEvent.addListener(map, 'click', function(overlay, point) {
    map.clearOverlays(); //clearing the previous marker
    var lati = point.lat(); //Function to extract latitude
    var longi = point.lng(); //Function to extract longitude
    var marker = new GMarker(new GLatLng(lati, longi), { draggable: false }); //Setting the marker to clicked location
    map.addOverlay(marker); //adding the marker to the map
    //JQuery function to assign the lat and long to the values of textboxes.
    $('#LatTxt').val(lati);
    $('#LonTxt').val(longi);
   });
}
 
//This JQuery Function operates almost the same as the onload function, except more earlier
$(function() {
   initialize();//call to initialize the map.
}

gistfile3.html

<div id="map_canvas" style="width: 600px; height: 400px;">
 </div>
<label>
 Latitude
 <input id="LatTxt" disabled="disabled" type="text" />
</label>
<label>
 Longitude
 <input id="LonTxt" disabled="disabled" type="text" />
</label>