var map;
    var geoXml2 = new GGeoXml("http://www.gpsbrianza.com/_KML/marathon_corto.kml");    
	var geoXml = new GGeoXml("http://www.gpsbrianza.com/_KML/marathon_lungo.kml");
    var toggleState = 1;

function onLoad() {
  if (GBrowserIsCompatible()) {
    map = new GMap2(document.getElementById("map")); 
    map.addControl(new GSmallMapControl());
	map.addControl(new GMapTypeControl());
    map.setCenter(new GLatLng(45.707890,9.380525), 12, G_HYBRID_MAP); 
	
    map.addOverlay(geoXml);
  }
} 


var txt1 ="Vai al percorso corto";
var txt2 ="Vai al percorso lungo";

function toggleMyKml() {

  if (toggleState == 1) {
    map.removeOverlay(geoXml);
	map.addOverlay(geoXml2);
    document.getElementById('togglePercorsi').value = txt1;
    toggleState = 0;
  } else {
    map.removeOverlay(geoXml2);
	map.addOverlay(geoXml);
	document.getElementById('togglePercorsi').value = txt2;
    toggleState = 1;
  }
}