AJAX通话仅工作一次

Question

Here's my code:

<script type="text/javascript">
    $(document).ready(function() {
      $('#username').change(check_username);
    });

    function check_username() {
      $("#check_username").html('<img src="images/site/ajax-loader.gif" />username avilable??').delay(5000);
      var usernametotest = $('#username').val();    
      $.post("backend/username_available.php", { username: usernametotest})
       .done(function(data) {
         $("#check_username").replaceWith(data);
       });
    }
</script>

I use this code for checking with AJACX the availability of a username in my form. It works perfect but just once. When an username is occupied and I change the username, no AJAX checks are done after the first one? The text "username already exists" (in the variable data), is not replaced by "username ok".

This JavaScript is added just before the </html> tag.

Answer 1

You could try this:

$('#username').on('change', function() {

  // write your code here

});