function createRequestObject()
{
        var ro;
        var browser = navigator.appName;
        if(browser == "Microsoft Internet Explorer"){
                ro = new ActiveXObject("Microsoft.XMLHTTP");
        }else{
                ro = new XMLHttpRequest();
        }
        return ro;
}

var http = createRequestObject();


/*
 * doRequest
 * 
 * arguments  : 
 *                url => string
 *                callback => function
 *                method => "post" or "get"
 */
function doRequest(url, args, callback, method )
{
        http.open( method, url, true);
        http.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        http.onreadystatechange = callback;
        http.send(args);
}