// allows for network timeouts with ajax calls
// uses prototype a little

function callInProgress(xmlhttp) {
  switch (xmlhttp.readyState) {
    case 1: case 2: case 3:
      return true;
      break;
    // Case 4 and 0
    default:
      return false;
    break;
  }
}

function showFailureMessage() {
  $('progress').update('Error: the network connection timed out');
  $('progress').show();
}

// Register global responders that will occur on all AJAX requests
Ajax.Responders.register( 
{
  onCreate: function(request) {
    request['timeoutId'] = window.setTimeout(
      function() {
        // If we have hit the timeout and the AJAX request is active, abort it and let the user know
        if (callInProgress(request.transport)) {
          request.transport.abort();
          showFailureMessage();
          // Run the onFailure method if we set one up when creating the AJAX object
          if (request.options['onFailure']) {
            request.options['onFailure'](request.transport, request.json);
          }
        }
      },
      5000 // Five seconds
    );
  },
  onComplete: function(request) {
    // Clear the timeout, the request completed ok
    window.clearTimeout(request['timeoutId']);
  }
}
);