Saving a Form with Custom Button I am trying to create a custom button that modifies a field in a form then saves the form in the same way as the default save button. The following code creates the button but I am having trouble finding where/how to perform the operation that clicking the default save button executes, with validation and updating every field before executing my submit code. 

function mymodule_form_alter(&amp;$form, &amp;$form_state, $form_id) {


     if ($form_id == 'submission_node_form') {
         $form['actions']['final_submit'] = array(
            '#type'   =&gt; 'submit',
            '#value'  =&gt; t('Submit'),
            '#submit' =&gt; array('mymodule_form_final_submit')
         );
     }  

}

function mymodule_form_final_submit($form, &amp;$form_state) {

}
A simple way is calling drupal_form_submit  in your custom module

function mymodule_form_final_submit($form, &amp;$form_state) {

  drupal_form_submit('submission_node_form', $form_state);

}