Customizing title of a modalframe

Either by customizing the title of the page you are loading (using normal Drupal tricks) or in Javascript loaded in a custom module.

I wonder how this can be done for Drupal 7 with javascript modification. Unfortunately, the following code doesn't work for title part:

Drupal.automodal.settingsAlter.testing = function(settings) {
  settings.autoFit = false;
  settings.width = 840;
  settings.height = 530;
  settings.title = 'Custom title' ;
  return settings;
}