function createRequestObject() {
	var ro;
	
	if(navigator.userAgent.indexOf("Opera")!=-1 && parseInt(navigator.userAgent.charAt(navigator.userAgent.indexOf("Opera") + 6)) >= 8){
		ro = new XMLHttpRequest();
	}else{
		if(navigator.appName == "Microsoft Internet Explorer"){
			ro = new ActiveXObject("Microsoft.XMLHTTP");
		}else{
			ro = new XMLHttpRequest();
		}//if
	}//if

	return ro;
}//createRequestObject

function sendRequest(url, returnfunction) {
	if(!isRequestBusy()){
		try{
			http.open('get', url, true);
			http.onreadystatechange = function() { 
				if(http.readyState == 4 && http.status == 200){
					returnfunction(http.responseText);
				}//if
			}//http.onreadystatechange
			http.send(null);
		}catch(err){
			//alert(err);
		}//try
	}else{
		var timeoutId = window.setTimeout(function(){ sendRequest(url, returnfunction) }, 100);	
	}//if
}//sendRequest

function isRequestBusy(){
	switch(http.readyState){
		case 1: 		return true;
						break;
		case 2: 		return true;
						break;
		case 3: 		return true;
						break;
		default:		return false;
						break;
	}//switch
}//isRequestBusy

var http = createRequestObject();