AJAX

Choose your user name

Min 6 characters

This example does not use XML. The server side PHP code checkName.php handles the JavaScript checkName callback by reading a simple text file containing names and returning a string. View this page's source to see the JavaScript.

This script accepts a GET parameter n containing the name to check. This is compared to entries in a text file names.txt. The check could just as easily be against a database. Possible return values are 'tooShort', 'taken' and 'available'.

 <?php
 header('Content-type: text/plain');
 $userName = $_GET['n'];
 if ( strlen($userName) < 6 ) exit('tooShort');
 $names = file('names.txt');
 foreach($names as $v) {
   if ( $userName == rtrim($v) ) exit('taken');
 }
 exit('available');
 ?>