var xmlHttp;

function createXMLHttpRequest() {
    if (window.ActiveXObject) {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    } 
    else if (window.XMLHttpRequest) {
        xmlHttp = new XMLHttpRequest();
    }
}
    


        
function checklogin(login,oldlogin) {
createXMLHttpRequest();
xmlHttp.onreadystatechange = responsechecklogin;
xmlHttp.open("GET", "http://localhost/sigma/ajax/ajax.php?action=checklogin&url="+login+"&oldlogin="+oldlogin, true);
xmlHttp.send(null);
}

function responsechecklogin() {
if(xmlHttp.readyState == 4) {
if(xmlHttp.status == 200) {
document.getElementById("result").innerHTML = xmlHttp.responseText;
}
}
}