Untitled

<html>
<head>
<script language="javascript">
function postRequest(strURL){
var xmlHttp;
if(window.XMLHttpRequest){ // For Mozilla, Safari, ...
var xmlHttp = new XMLHttpRequest();
}
else if(window.ActiveXObject){ // For Internet Explorer
var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlHttp.open('POST', "login.php", true);
xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xmlHttp.onreadystatechange = function(){
if (xmlHttp.readyState == 4){
updatepage(xmlHttp.responseText);
}
}
xmlHttp.send(strURL);
}

function updatepage(str){
if(str=="yes"){
alert("Welcome User");
}else{
alert("Invalid Login! Please try again!");
}
}

function call_login(){
var username = window.document.f1.username.value;
var password = window.document.f1.password.value;
var url = "username=" + username + "&password=" +password ;
postRequest(url);
}
</script>
</head>

<body>
<Center>

<form name="f1" onsubmit="return call_login();">
<table border="0" bgcolor="#CCCCFF" cellspacing="1" cellpadding="3" width="287">
<tr>
<td align="left" colspan="2" width="275"><b><font size="5" color="#000080">Login</font></b></td>
</tr>
<tr>
<td align="right" width="81"><b><font color="#000080">User
Name:</font></b></td>
<td width="184"><input type="text" name="username" id="user" size="20" value="" /></td>
</tr>
<tr>
<td align="right" width="81"><b><font color="#000080">Password:</font></b></td>
<td width="184"><input type="password" name="password" size="20" value="" /></td>
</tr>
<tr>
<td colspan="2" align="center" width="275"><input type="button" name="a1" value="Login" onclick="call_login()"></td>
</tr>
</table>
</form>

</center>
</body>
</html>