AJAX JSON request (js)

gistfile1.txt

$(function() {

// On unfocus, check the value of the username field, and
// store that in a variable.
  $("#username").focusout(function() {
    var usernameInput = $(this).val();

    // We want to take that variable and send the variable to
    // the "server" and get back a JSON hash

    $.getJSON(
      '/usernames.json',
      usernameInput,
      function(returndata, coolstatus ) {
        var fieldset = $('#username').closest('fieldset');
        if (returndata['valid'] === '0') {
          fieldset.append("Invalid Username");
        } else {
          // Then, we want to check that hash...if its valid, do nothing,
          // else, indicate that to the user (that username is taken, or something)
          fieldset.append("Great Username");
        }
      }
    );
  });
});