var centerLatitude = 39.20944462650;
var centerLongitude = -77.62111249300;
var startZoom = 11;
var map;
 
function init()
{
  if (GBrowserIsCompatible()) {
    document.getElementById('button-sidebar-hide').onclick = function() { return changeBodyClass('sidebar-right', 'nosidebar'); };
    document.getElementById('button-sidebar-show').onclick = function() { return changeBodyClass('nosidebar', 'sidebar-right'); };  	
    map = new GMap2(document.getElementById("map"));
    var location = new GLatLng(centerLatitude, centerLongitude);
    map.setCenter(location, startZoom);
    map.addControl(new GSmallMapControl());
    map.addControl(new GMapTypeControl());
    map.addControl(new GOverviewMapControl());
    retrieveMarkers()
  }
}
 
window.onload = init;
 
function createMarker(latlng, html) {
    var marker = new GMarker(latlng);
    GEvent.addListener(marker, 'click', function() {
    var markerHTML = html;
    marker.openInfoWindowHtml(markerHTML);
    });
return marker;
}
 
function retrieveMarkers() {
   var request = GXmlHttp.create();
 
   //tell the request where to retrieve data from.
   request.open("GET", "data.xml", true);
 
   //tell the request what to do when the state changes.
   request.onreadystatechange = function() {
   if (request.readyState == 4) {
   var xmlDoc = request.responseXML;
 
   var markers = xmlDoc.documentElement.getElementsByTagName("marker");
   for (var i = 0; i < markers.length; i++) {
      var lng = markers[i].getAttribute("lng");
      var lat = markers[i].getAttribute("lat");
      //check for lng and lat so MSIE does not error
      //on parseFloat of a null value
      if(lng && lat) {
         var latlng = new GLatLng(parseFloat(lat),parseFloat(lng));
         var html = '<div><b>Site: </b> '
         + markers[i].getAttribute("NAME")
         //+ '<p> + <img border="0" src=" ' 
         //+ markers[i].getAttribute("grph") 
         //+ " >'
         + '</div>';
         var marker = createMarker(latlng, html);      
         map.addOverlay(marker);      
         }
      } //for
   } //if
} //function
 
request.send(null);
}
 
function changeBodyClass(from, to) {
	document.body.className = document.body.className.replace(from, to);
	return false;
}