[SOLVED] Ajax not responding ?

[balkan7]

i have created code for check username, but ajax nothing respond me

 

code is:

 

<script>
function createRequestObject() {
var req;
if(window.XMLHttpRequest){
	// Firefox, Safari, Opera...
	req = new XMLHttpRequest();
} else if(window.ActiveXObject) {
	// Internet Explorer 5+
	req = new ActiveXObject("Microsoft.XMLHTTP");
} else {
	// There is an error creating the object,
	// just as an old browser is being used.
	alert('Problem creating the XMLHttpRequest object');
}
return req;

}
var http = createRequestObject();
function useHttpResponseusername() {
  if (http.readyState == 4) {
var textOut = http.responseText;
var update = new Array();

document.getElementById('usercheck').innerHTML = textOut;
if(textOut.indexOf('|' != -1)) {
            update = textOut.split('|');
            document.getElementById(update[0]).innerHTML = update[1];
        }
  }
}
function checkusername(username) {
http.open('get', 'register.php?check=true&checkusername='+username+'&rand='+Math.random(), true);
http.onreadystatechange = useHttpResponseusername;
http.send(null);
}
</script>

 

php code:

<?php if(isset($_GET['check'])) {
echo "<style type='text/css'>
.quoteerror {
	color : #FFFFFF;
	background-color : #FF0000;
	border : 1px solid #C11B17;
}
</style>";
if(isset($_GET['checkusername'])) {
	$username = stripinput(trim(eregi_replace(" +", " ", $_GET['checkusername'])));
	if (!preg_match("/^[-0-9A-Z_@\s]+$/i", $username)) echo "<div class='quoteerror'><center>".$locale['403']."</center></div>";
	$result = dbquery("SELECT * FROM ".DB_USERS." WHERE user_name='$username'");
	if (dbrows($result) != 0) {
		$ajax_responde = "checkusername|<img src='images/icon_ajax_false.gif' border='0'> <span style='color: #FF0000;'>This username has already been taken</span>";
	} else {
		$ajax_responde = "checkusername|<img src='images/icon_ajax_true.gif' border='0'> <span style='color: #008000;'>This username is still available.</span>";
	}
	die();
}
}
?>

 

and

<input type='text' name='username' maxlength='30' class='textbox' style='width:200px;' onChange='checkusername(this.value)' /><div id='usercheck'></div>