text: var map; // The map object
  var myCentreLat = 53.8;
  var myCentreLng = -1.6;
  var initialZoom = 12;
  // same kind of functionality as excercise 4.1's dynamicMarkers.js bar the conversion of coordinates and omission of genhex 
  function infoCallback(infowindow, marker) {
  	return function() {
  		infowindow.open(map, marker);
  	};
  }
  
  function addMarker(myPos,myTitle,myInfo) {
  	var marker = new google.maps.Marker({
  		position: myPos,
  		map: map,
  		title: myTitle,
                  icon: 'blue_plaque.png'//Changes icon from default to specified image file providing the image is in the same directory
  	});
     var infowindow = new google.maps.InfoWindow({content: myInfo});
     
     google.maps.event.addListener(marker,'click', infoCallback(infowindow, marker));
  }
  
  function initialize() {
     var latlng = new google.maps.LatLng(myCentreLat,myCentreLng);
     var myOptions = {
  		zoom: initialZoom,
  		center: latlng,
  		mapTypeId: google.maps.MapTypeId.ROADMAP,
                  
     };
     
     map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
  
     for (id in os_markers) {
  		var info = "<div class=infowindow><h1>" +
  			os_markers[id].title + "</h1><p>Caption: " + os_markers[id].caption + "</p></div>";
  
  		// Convert co-ords original coordinate reference system OSGB36 so that they are compatible with the default reference system for google maps which is  WGS 84 Web Mercator
  		var osPt = new OSRef(
  			os_markers[id].easting,os_markers[id].northing);
  		
  		var llPt = osPt.toLatLng(osPt);
  		llPt.OSGB36ToWGS84();
  
  		addMarker(
  			new google.maps.LatLng(llPt.lat,llPt.lng),
  			os_markers[id].title,info);
     }
  }
  