selectStud javascript

// JavaScript Document

function GetXmlHttpObject()
{
    var xmlHttp=null;
    if(window.XMLHttpRequest){
        xmlHttp=new XMLHttpRequest();    // code for IE7+, Firefox, Chrome, Opera, Safari
    }else{
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");   // code for IE6, IE5
    }
    return xmlHttp;
}

function stateChanged()
{
    return function () {
        if (xmlHttp.readyState==4 && xmlHttp.status==200){
            document.getElementById("txtHint").innerHTML=xmlHttp.responseText;
        }
    }
}

function showStud(id)
{
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null)
    {
        alert ("Browser does not support HTTP Request");
        return;
    }
    var url="getStud.php";
    xmlHttp.onreadystatechange=stateChanged;
    xmlHttp.open("POST",url,true);
    xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
    xmlHttp.send("q="+id);
}

function addStud(id, ln, fn)
{
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null)
    {
        alert ("Browser does not support HTTP Request");
        return;
    }
    var url="addStud.php";

    xmlHttp.onreadystatechange=stateChanged;
    xmlHttp.open("POST",url,true);
    xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
    xmlHttp.send("q1="+id+"&q2="+ln+"&q3="+fn);
}

function editStud(id, ln, fn)
{
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null)
    {
        alert ("Browser does not support HTTP Request");
        return;
    }
    var url="editStud.php";
    xmlHttp.onreadystatechange=stateChanged;
    xmlHttp.open("POST",url,true);
    xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
    xmlHttp.send("q1="+id+"&q2="+ln+"&q3="+fn);
}

function deleteStud(id)
{
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null)
    {
        alert ("Browser does not support HTTP Request");
        return;
    }
    var url="deleteStud.php";
    url=url+"?q="+id;
    xmlHttp.onreadystatechange=stateChanged;
    xmlHttp.open("POST",url,true);
    xmlHttp.send(null);
}