function getHTTPObject(){
    if (window.ActiveXObject) return new ActiveXObject("Microsoft.XMLHTTP");
    else if (window.XMLHttpRequest) return new XMLHttpRequest();
    else {
        alert("Your browser does not support AJAX.");
        return null;
        }
}

function setCredit(){
    if(httpObject.readyState == 4){
         var spanEl = document.getElementById('credit');
         if(httpObject.responseText!='_')
            spanEl.childNodes[0].nodeValue = httpObject.responseText;

    }
}

function getCredit(user){
    httpObject = getHTTPObject();
    if (httpObject != null) {
        httpObject.open("GET", "elements/get_credit.php?user="+user, true);
        httpObject.send(null);
        httpObject.onreadystatechange = setCredit;

    }
}

var httpObject = null;