function getConnection() 
{
	var obj=null;
	if(window.ActiveXObject) // Internet Explorer
	{
		var ieversions = 'Msxml2.XMLHTTP,Microsoft.XMLHTTP,Msxml2.XMLHTTP.5.0,Msxml2.XMLHTTP.4.0,Msxml2.XMLHTTP.3.0'.split(",")
		for(var i=0; !obj && i<ieversions.length; i++)
		{
			try
			{
				obj = new ActiveXObject(ieversions[i]);
			}
			catch(e)
			{
				obj = null;
			}
		}
	}else if(window.XMLHttpRequest) // Firefox et autres
	{
		obj = new XMLHttpRequest();
	}
	
	return obj;
}

function setupCall(url,callback)
{
	var conn;
	conn=getConnection();
	if(conn==null) return;
	conn.open('GET',url,true);
	conn.onreadystatechange=callback;
	//conn.send();
	return conn;
}

function disposeCall(conn)
{
	conn.onreadystatechange = function() {};
	conn.abort();
}