var centerLatitude = 51.6245687124;
 var centerLongitude = -0.779569393298;
 var startZoom = 10;
 var map;

function init() {
    
	map = new GMap2(document.getElementById("map"));
	
    //Set minimum and maximum zoom levels
    G_PHYSICAL_MAP.getMinimumResolution = function () { return 4 };
    G_NORMAL_MAP.getMinimumResolution = function () { return 4 };
    G_SATELLITE_MAP.getMinimumResolution = function () { return 4 };
    G_HYBRID_MAP.getMinimumResolution = function () { return 4 };

    G_PHYSICAL_MAP.getMaximumResolution = function () { return 14 };
    G_NORMAL_MAP.getMaximumResolution = function () { return 14 };
    G_SATELLITE_MAP.getMaximumResolution = function () { return 14 };
    G_HYBRID_MAP.getMaximumResolution = function () { return 14 }; 
	
    //add controls
    map.addControl( new GLargeMapControl());
    
	map.setCenter(new GLatLng(centerLatitude, centerLongitude), startZoom);
	
	
	// Create a base icon for all of our markers that specifies the
    // shadow, icon dimensions, etc.
    var baseIcon = new GIcon();
    baseIcon.shadow = "http://www.google.com/mapfiles/shadow50.png";
    baseIcon.iconSize = new GSize(20, 34);
    baseIcon.shadowSize = new GSize(37, 34);
    baseIcon.iconAnchor = new GPoint(9, 34);
    baseIcon.infoWindowAnchor = new GPoint(9, 2);
    baseIcon.infoShadowAnchor = new GPoint(18, 25);	
	
	function addMarker(point, markernumber, job_id, job_title, salary, close_date, contract_desc) {

          // Create a lettered icon for this point using our icon class
          var letter = String.fromCharCode("A".charCodeAt(0) + markernumber);
          var letteredIcon = new GIcon(baseIcon);
          letteredIcon.image = "http://www.google.com/mapfiles/marker" + letter + ".png";

          // Set up our GMarkerOptions object
          markerOptions = { icon:letteredIcon };
		  
          var marker = new GMarker(point, markerOptions);
		  
          //GEvent.addListener(marker, "click", function() {
          //  location.href='#'
          //});

          return marker;

	}
	
	var mapBounds = map.getBounds();
	var southWest = mapBounds.getSouthWest();
	var northEast = mapBounds.getNorthEast();
	var newBounds = new GLatLngBounds(southWest, northEast);	
	
	for (id in markers) {//itterating through markers
		
		//create new GLatLang
		var point = new GLatLng(markers[id].latitude, markers[id].longitude);
		var marker = addMarker(point, markers[id].markernumber, markers[id].job_id, markers[id].job_title, markers[id].salary, markers[id].close_date, markers[id].contract_desc)
		map.addOverlay(marker);
		
		//Extend newBounds so that this point is inside		
		newBounds.extend(point);
	
	
	}
	
	// Find zoom level that will show all of the points
	var level = map.getBoundsZoomLevel(newBounds);
	
	if (level-1 <= startZoom) { 
		map.setZoom(level-1);
	}
	
	map.setCenter(newBounds.getCenter());
}

function loadurlMaps(dest) {

	  try {
          // Moz supports XMLHttpRequest. IE uses ActiveX.
          // browser detction is bad. object detection works for any browser
          jsonhttp = window.XMLHttpRequest?new XMLHttpRequest(): new ActiveXObject("Microsoft.XMLHTTP");
      } catch (e) {
          // browser doesn't support ajax. handle however you want
      }
	 
      // the xmlhttp object triggers an event everytime the status changes
      // triggered() function handles the events

      jsonhttp.onreadystatechange = triggeredMaps;

      // open takes in the HTTP method and url.
      jsonhttp.open("GET", dest);
       
      // send the request. if this is a POST request we would have
      // sent post variables: send("name=aleem&gender=male)
      // Moz is fine with just send(); but
      // IE expects a value here, hence we do send(null);
      jsonhttp.send(null);
}

function triggeredMaps() {
      // if the readyState code is 4 (Completed)
      // and http status is 200 (OK) we go ahead and get the responseText
      // other readyState codes:
      // 0=Uninitialised 1=Loading 2=Loaded 3=Interactive
      

      if ((jsonhttp.readyState == 4) && (jsonhttp.status == 200)) {
         // jsonhttp.responseText object contains the response.
		 //var markers = eval('(' + jsonhttp.responseText + ')');
 		
 		 //first delete all old references scripts with id=mapData
         var mapData = document.getElementById("mapData");
         var head = document.getElementsByTagName("head")[0];
         if (mapData) {
         	head.removeChild(mapData);
         }
         
         //alert(jsonhttp.responseText);

		 //create new script
         newScript=document.createElement('script');
         document.getElementsByTagName('head')[0].appendChild(newScript);
         newScript.id = "mapData";
         newScript.type = "text/javascript";
         newScript.language = "javascript"; 
         newScript.text = jsonhttp.responseText; 
         
         //alert(markers.length);
         
         init();
		 
      }
}