var req = null; // XMLHttpRequest Object

var init = function() {
   try { // firefox, safari, ie7
   req = new XMLHttpRequest(); }catch(e) {
   try { // later ie
   req = new ActiveXObject('MSXML2.XMLHTTP');}catch(e) {
   try { //early ie
   req = new ActiveXObject('Microsoft.XMLHTTP');} catch(e) {
   return false;}}}
   return req;
}

var doGet = function(url, handler) {
	if(init()) {
		req.open('GET', url, true);
		req.send(null);
		req.onreadystatechange = function() {
			if (req.readyState == 4) {
		    		if(req.statusText == 'OK') {
		        		handler(req.responseText);
		    		}
			}
	    	}
	}
}