custom module: drupal_add_js and drupal_add_css do not work after form validation? I have created a custom module that changes the layout &amp; adds extra functionality to one of my content type creation and edit forms.

It works beautifully and as expected apart from when I submit the form with, for example, a blank node title or any other required fields.

The page is reloaded as expected with the error message, the form modifications are loaded from the module (field #prefix, #suffix etc..) but the css and the js are not loaded.

Here is the code I have:

/**
* Implementation of HOOK_form_alter()
*/
function mymodule_entry_form_modify_form_alter(&amp;$form, $form_state, $form_id) {

  // 1.ENTRY FORM
  if ($form_id == 'entry_node_form') {

  // here were some form field modifications i removed


/* 1.3 LAYOUT - ADD JAVASCRIPT FILES
 * Add .js files
 */
// add jquery script before calling it
drupal_add_js(drupal_get_path('module', 'mymodule') . '/includes/js/jquery.fixheight.js');
// call the script
drupal_add_js(drupal_get_path('module', 'mymodule') . '/includes/js/mymodule_entry_form_modify.js');


/* 1.4 LAYOUT - ADD CSS FILES
 * Add .css files
 */
drupal_add_css(drupal_get_path('module', 'mymodule') . '/includes/css/mymodule_entry_form_modify.css');    

 }
}


Can anyone explain why this happens?
I don't use D7, but I believe you should be using #attached and it should fix your issue.