var http = createRequestObject();
function createRequestObject(){
    var request_;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        request_ = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else{
        request_ = new XMLHttpRequest();
    }
    return request_;
}
function getInfo(){
    http.open('get', 'check_name.php?user='+ document.regi.username.value);
    http.onreadystatechange = handleInfo;
    http.send(null);
}

function getInfo2(){
    http.open('get', 'act/sop.php?id='+ document.form1.subject.selectedIndex);
    http.onreadystatechange = handleInfo;
    http.send(null);
}

function handleInfo(){
    if(http.readyState == 1){
        document.getElementById('mydiv').innerHTML = '<img border="0" src="images/loadingu.gif" width="16" height="16">';
    }
    if(http.readyState == 4){
        var response = http.responseText;
        document.getElementById('mydiv').innerHTML = response;
    }
}