var xmrReq;
var xmrCallback;
var xmrArg

function xmrGetDoc(url,callback,arg)
{
	var xmr=null;
	try {
		if (window.XMLHttpRequest) {
			xmr = new XMLHttpRequest();
		} else if (window.ActiveXObject) {
			try {
				xmr = new ActiveXObject("Microsoft.XMLHTTP");
			} catch(e) {
				xmr = new ActiveXObject("Msxml2.XMLHTTP");
			}
		}
	} catch(e) {
	}
	if (xmr) {
		xmrReq=xmr;
		xmrCallback = callback;
		xmrArg = arg;
		xmr.onreadystatechange = xmrOnReqChanged;
		xmr.open("GET", url, true);
		xmr.send("");
	}
}

function xmrOnReqChanged()
{
	// only if req shows "loaded"
   if (xmrReq.readyState==4 && xmrReq.status==200) {
		xmrCallback(xmrReq.responseText, xmrArg);
	}
}