Untitled

 -- js file
function makeXHR(){
    var xhr = null;
    try {
        xhr = new XMLHttpRequest();  // Firefox, Opera, ...
    } catch(err1) {
        try {
            xhr = new ActiveXObject("Microsoft.XMLHTTP"); //Noen IE
        } catch(err2) {
            try {
                xhr = new ActiveXObject("Msxml2.XMLHTTP");  //Noen IE
            } catch(err3) {
                xhr = null;
            }
        }
    }
    return xhr;
}

var xmlhttp;

function getMsgFromServer(){
    xmlhttp = makeXHR();
    if(xmlhttp == null){
        alert("Your browser does not support xmlhttp");
        return;
    }
    var url = "passwordcheck.php";
    url += "?user="+document.getElementById("user").value;
    url += "&pass="+document.getElementById("pass").value;
    url=url+"&sid="+Math.random();
    xmlhttp.onreadystatechange=stateChanged;
    xmlhttp.open("GET",url,true);
    xmlhttp.send(null);
}

function stateChanged()
{
    if (xmlhttp.readyState==4)
    {
        document.getElementById("messageGoesHere").innerHTML=xmlhttp.responseText;
    }
}

-- html file

<!--
To change this template, choose Tools | Templates
and open the template in the editor.
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>Oppgave 1</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script src="jsfuncs.js" type="text/javascript"></script>
  </head>
  <body>
      <form>
          Username: <input type="text" id="user"/>
          <br>
          Password: <input type="text" id="pass"/>
          <br>
          <input type="submit" onclick="getMsgFromServer()"/>
      </form>
      <div id="messageGoesHere">

      </div>
  </body>
</html>


---- php file ---

<?php
//checks if username and password are as expected.

if (    ($_GET['user'] == "john")
        &&
        ($_GET['pass'] == "1234")
) {
    echo "Dis be secret message";
}
else {
    echo "You are gay";
}
?>