var req;

function submitForm(input) {
    var xhr;
    try { xhr = new ActiveXObject('Msxml2.XMLHTTP'); }
    catch (e) {
        try { xhr = new ActiveXObject('Microsoft.XMLHTTP'); }
        catch (e2) {
            try { xhr = new XMLHttpRequest(); }
            catch (e3) { xhr = false; }
        }
    }
    xhr.onreadystatechange = function() {
        if (xhr.readyState == 4) {
            if (xhr.status == 200) {
                document.getElementById("gradeDiv").innerHTML = xhr.responseText;
            } else {
                document.gradeDiv="Error code "+xhr.status;
            }
        }
    };
    xhr.open("GET", "./grades.php?studentID="+input, true);
    xhr.send(null);
}