var agt = navigator.userAgent.toLowerCase();
var is_op = (agt.indexOf("opera") != -1);
var is_ie = (agt.indexOf("msie") != -1) && document.all && !is_op;
var is_ie5 = (agt.indexOf("msie 5") != -1) && document.all && !is_op;

function CreateXmlHttpReq(handler) {
  var xmlhttp = null;
  if (is_ie) {
    var control = (is_ie5) ? "Microsoft.XMLHTTP" : "Msxml2.XMLHTTP";

    try {
      xmlhttp = new ActiveXObject(control);
      xmlhttp.onreadystatechange = handler;
    }
	catch (ex) {
      alert("You need to enable active scripting and activeX controls");  
    }

  }
  else {
		xmlhttp = new XMLHttpRequest();
		xmlhttp.onload = handler;
		xmlhttp.onerror = handler;
	}
	return xmlhttp;
}

function XmlHttpPOST(xmlhttp, url, data) {
	try {
		xmlhttp.open("POST", url, true);
		xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;");
		xmlhttp.setRequestHeader("Content-length", data.length);
		xmlhttp.setRequestHeader("Connection", "close");
		xmlhttp.send(data);
	}
	catch (ex) {
	}
}

function XmlHttpGET(xmlhttp, url) {
	try {
		xmlhttp.open("GET", url, true);	
		xmlhttp.send(null);
	}
	catch (ex) {
	}
}