public/javascripts/inputex/js/fields/MapField.js
function(superwrapper) {
			if (window.VEMap) {
				return;
			}

			var preloader = 'MapVEPreloader_' + inputEx.MapFieldsNumber;
			inputEx[preloader] = function() {
				superwrapper.wait_create();
			};

			/*
			 *	Fixes the 'p_elSource.attachEvent is not a function' error
		 	 *	http://www.google.ca/search?hl=en&q=p_elSource.attachEvent+is+not+a+function&btnG=Google+Search&meta=
			 *	
			 */
			if (!window.attachEvent) {
				var script = document.createElement("script");
				script.src = "http://dev.virtualearth.net/mapcontrol/v6.2/js/atlascompat.js";
				script.type = "text/javascript";

				document.getElementsByTagName("head")[0].appendChild(script);
			}

			var script = document.createElement("script");
			script.src = "http://dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6.2&onScriptLoad=inputEx." + preloader;
			script.type = "text/javascript";

			document.getElementsByTagName("head")[0].appendChild(script);

			return	true;
		}
function(superwrapper) {
			if (window.VEMap) {
				return;
			}

			var preloader = 'MapVEPreloader_' + inputEx.MapFieldsNumber;
			inputEx[preloader] = function() {
				superwrapper.wait_create();
			};

			/*
			 *	Fixes the 'p_elSource.attachEvent is not a function' error
		 	 *	http://www.google.ca/search?hl=en&q=p_elSource.attachEvent+is+not+a+function&btnG=Google+Search&meta=
			 *	
			 */
			if (!window.attachEvent) {
				var script = document.createElement("script");
				script.src = "http://dev.virtualearth.net/mapcontrol/v6.2/js/atlascompat.js";
				script.type = "text/javascript";

				document.getElementsByTagName("head")[0].appendChild(script);
			}

			var script = document.createElement("script");
			script.src = "http://dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6.2&onScriptLoad=inputEx." + preloader;
			script.type = "text/javascript";

			document.getElementsByTagName("head")[0].appendChild(script);

			return	true;
		}
function ( superwrapper ) { if ( window . VEMap ) { return ; } var preloader = 'MapVEPreloader_' + inputEx . MapFieldsNumber ; inputEx [ preloader ] = function ( ) { superwrapper . wait_create ( ) ; } ; /*
			 *	Fixes the 'p_elSource.attachEvent is not a function' error
		 	 *	http://www.google.ca/search?hl=en&q=p_elSource.attachEvent+is+not+a+function&btnG=Google+Search&meta=
			 *	
			 */ if ( ! window . attachEvent ) { var script = document . createElement ( "script" ) ; script . src = "http://dev.virtualearth.net/mapcontrol/v6.2/js/atlascompat.js" ; script . type = "text/javascript" ; document . getElementsByTagName ( "head" ) [ 0 ] . appendChild ( script ) ; } var script = document . createElement ( "script" ) ; script . src = "http://dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6.2&onScriptLoad=inputEx." + preloader ; script . type = "text/javascript" ; document . getElementsByTagName ( "head" ) [ 0 ] . appendChild ( script ) ; return true ; }
If Virtual Earth has not been added via script tag, this
will download it for you

http://soulsolutions.com.au/Blog/tabid/73/EntryID/519/Default.aspx
p_elSource.attachEvent is not a function
If Virtual Earth has not been added via script tag this will download it for you