var stamarkers=[];

function getStations() {
  stamarkers = [];
  var request = GXmlHttp.create();
  request.open("GET", staXML, true);
  request.onreadystatechange = function() {
    if (request.readyState == 4) {
      var xmlDoc = GXml.parse(request.responseText);
      var markers = xmlDoc.documentElement.getElementsByTagName("marker");
      for (var i = 0; i < markers.length; i++) {
        // obtain the attribues of each marker
        var stalat = parseFloat(markers[i].getAttribute("lat"));
        var stalng = parseFloat(markers[i].getAttribute("lng"));
        var stapoint = new GLatLng(stalat.toFixed(3),stalng.toFixed(3));
        var staname = markers[i].getAttribute("station");
        var stahtml = LAB+'Station: </a>'+vals+staname+'</a><br>'+LAB+'Latitude: </a>'+vals+stalat+'</a><br>'+LAB+'Longitude: </a>'+vals+stalng+'</a>';
        // create the marker
        createSTAMarker(stapoint,stahtml);
      }
    }
  }
  setTimeout("addStations()",500);
  request.send(null);
}

function createSTAMarker(point,html) {
	var marker = new GMarker(point,{icon:sta_icon});
	GEvent.addListener(marker, "click", function() {
		marker.openInfoWindowHtml(html);
	});
	stamarkers.push(marker);
}


function addStations() {
  for (var i = 0; i < stamarkers.length; i++) {		
 		map.addOverlay(stamarkers[i]);
 		stamarkers[i].hide();
 	}
}


function hideStations() {
  for (var i = 0; i < stamarkers.length; i++) {		
		stamarkers[i].hide();
	}
}


function showStations() {
  for (var i = 0; i < stamarkers.length; i++) {		
		stamarkers[i].show();
	}
}


function replotStations() {
  if (document.getElementById("overlay").stations.checked) {
    showStations();
  }
  else {
    hideStations();
  }
}