var READY_STATE_UNITIALIZED=0;
var READY_STATE_LOADING=1;
var READY_STATE_LOADED=2;
var READY_STATE_INTERACTIVE=3;
var READY_STATE_COMPLETE=4;

var req=null;

function getXMLHTTPRequest()
{
    var xRequest = null;
    if(window.XMLHttpRequest)
    {
        xRequest = new XMLHttpRequest();
    }
    else if (typeof ActiveXObject != undefined)
    {
        xRequest = new ActiveXObject("Microsoft.XMLHTTP");
    }
    return xRequest;
}

function sendRequest(url, params, HttpMethod)
{
    if(!HttpMethod) HttpMethod = "GET";
    
    req = getXMLHTTPRequest();
    if(req)
    {
        req.onreadystatechange=onReadyStateChange;
        req.open(HttpMethod, url, true);
        req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        req.send(params);
    }
}