Drupal - Simple confirmation popup dialog box
I got it!!!
Here's a simple 100% functioning exmple:
$form['delete'] = array(
'#type' => 'submit',
'#value' => t('Delete'),
'#attributes' => array('onclick' => 'if(!confirm("Really Delete?")){return false;}'),
);
I hope this helps.
Happy coding :)
Drupal has a native confirm_form() function, but it is server side rather than Javascript based, which is what I assume you mean.