function getHTTPRequest() {
    var r = null;
    if(window.XMLHttpRequest) {
        try {
            r = new XMLHttpRequest();
        } catch(e) {
            r = false;
        }
    } 
    else if(window.ActiveXObject) {
        try {
            r = new ActiveXObject("Msxml2.XMLHTTP");
        } catch(e) {
            try {
                r = new ActiveXObject("Microsoft.XMLHTTP");
            } catch(e) {
                r = false;
            }
        }
    }
        return r;
}
    
function postTextRequest(url,params,func){
    var req = getHTTPRequest();
    if(req){
        req.open("POST", url+'?'+new Date().getTime(), true);
        req.setRequestHeader('Content-Type','application/x-www-form-urlencoded; charset=utf-8');
        req.onreadystatechange = function(){
            if(req.readyState == 4 ){
                if(req.status == 200 ){
                    func(req.responseText);
                }
            }
        }
        req.send( params );
    }
}