function makeMap(idname, xmlname, awidth, aheight, datafolder, markersfolder) {
	if (GBrowserIsCompatible()) {
		// arrays to hold copies of the markers and html used by the side_bar
		// because the function closure trick doesnt work there
		var gmarkers = [];
		var i = 0;
		// resize the map
		var m = document.getElementById(idname);
		m.style.width = awidth;
		m.style.height = aheight;
		
		var map = new GMap(m);
	  
		// Create our base marker icon 
		var icons = new Array();
		icons[""] = new GIcon(); 
		icons[""].image = "http://www.google.com/mapfiles/marker.png"; 
		icons[""].shadow= "http://www.google.com/mapfiles/shadow50.png"; 
		icons[""].iconSize=new GSize(20, 34); 
		icons[""].shadowSize=new GSize(37, 34); 
		icons[""].iconAnchor=new GPoint(9,34); 
		icons[""].infoWindowAnchor=new GPoint(9,2); 
		icons[""].infoShadowAnchor=new GPoint(18,25); 
		icons[""].printImage="http://www.google.com/mapfiles/markerie.gif"; 
		icons[""].mozPrintImage="http://www.google.com/mapfiles/markerff.gif"; 
		icons[""].printShadow="http://www.google.com/mapfiles/dithshadow.gif"; 
		icons[""].transparent="http://www.google.com/mapfiles/markerTransparent.png";
		icons[""].imageMap=[9,0,6,1,4,2,2,4,0,8,0,12,1,14,2,16,5,19,7,23,8,26,9,30,9,34,11,34,11,30,12,26,13,24,14,21,16,18,18,16,20,12,20,8,18,4,16,2,15,1,13,0]; 

		function numberedIcon(iconNumber) {
			//if (iconNumber.match(/\.png$/i)) {
		   if (isNaN(parseInt(iconNumber))) {
			  iconNumber = "";
		   } else if (!isNaN(parseInt(iconNumber)) && ((iconNumber < 0) || (iconNumber > 99))) {
			  iconNumber = "";
		   } else if ((typeof(iconNumber)=="undefined") || (iconNumber==null)) { 
			  iconNumber = "";
		   }
		   if (!icons[iconNumber]) {
			  var icon = new GIcon(icons[""]);
			  icon.image = markersfolder + "marker" + iconNumber + ".png";
			  icons[iconNumber]=icon;
		   } 
		   return icons[iconNumber];
		}

		// A function to create the marker and set up the event window
		function createMarker(point, name, html, iconStr) {
			var marker = new GMarker(point);
			if (iconStr) {
				marker = new GMarker(point, numberedIcon(iconStr));
			}
			GEvent.addListener(marker, "click", function() {
				marker.openInfoWindowHtml(html);
			});		
			gmarkers[i] = marker;
			i++;
			return marker;
		}
	  
		// This function picks up the click and opens the corresponding info window
		function myclick(i) {
		GEvent.trigger(gmarkers[i], "click");
		}
		
		// create the map
		var map = new GMap(document.getElementById(idname));
		map.addControl(new GSmallMapControl());
		map.addControl(new GMapTypeControl());
		map.setCenter(new GLatLng(0,0),0);

		// ===== Start with an empty GLatLngBounds object =====     
		var bounds = new GLatLngBounds();
		GDownloadUrl(xmlname, function(doc, responseCode) {	
			if(responseCode == 200) {
				var xmlDoc = GXml.parse(doc);
				// obtain the array of markers and loop through it
				var markers = xmlDoc.documentElement.getElementsByTagName("marker");
				for (var i = 0; i < markers.length; i++) {
					// obtain the attribues of each marker
					var lat = parseFloat(markers[i].getAttribute("lat"));
					var lng = parseFloat(markers[i].getAttribute("lng"));
					var point = new GLatLng(lat,lng);
					var html = markers[i].getAttribute("html");
					iTemp = html.match(/href='(?!(http|ftp))/ig);
					html = html.replace(html.match(/href='(?!(http|ftp))/ig), "href='".concat(datafolder)); //find href and at full url
					html = html.replace(html.match(/href="(?!(http|ftp))/ig), 'href="'.concat(datafolder)); //find href and at full url		
					html = html.replace(html.match(/src='(?!(http|ftp))/ig), "src='".concat(datafolder));  //find src and at full url	
					html = html.replace(html.match(/src="(?!(http|ftp))/ig), 'src="'.concat(datafolder));  //find src and at full url		
					var label = markers[i].getAttribute("label");
					var icon = markers[i].getAttribute("icon");
					// create the marker
					var marker = createMarker(point,label,html,icon);
					map.addOverlay(marker);
					// ==== Each time a point is found, extend the bounds ato include it =====
					bounds.extend(point);
				} //for
			
				// ========= Now process the polylines ===========
				var lines = xmlDoc.documentElement.getElementsByTagName("line");
				// read each line
				for (var a = 0; a < lines.length; a++) {
					// get any line attributes
					var colour = lines[a].getAttribute("colour");
					var width  = parseFloat(lines[a].getAttribute("width"));
					// read each point on that line
					var points = lines[a].getElementsByTagName("point");
					var pts = [];
						for (var i = 0; i < points.length; i++) {
							pts[i] = new GLatLng(parseFloat(points[i].getAttribute("lat")),
												 parseFloat(points[i].getAttribute("lng")));
							bounds.extend(pts[i]);
							}
					map.addOverlay(new GPolyline(pts,colour,width));
					bounds.extend(point);
				} //for
				
				// ===== determine the zoom level from the bounds =====
				map.setZoom(map.getBoundsZoomLevel(bounds));
				
				// ===== determine the centre from the bounds ======
				map.setCenter(bounds.getCenter());
		
			} else if(responseCode == -1) {
				alert("Data request timed out. Please try later.");
			} else { 
				alert("Request resulted in error. Check XML file is retrievable.");
			}
		}); //gdownloadurl
    } //if (GBrowserIsCompatible())
} //function makeMap