my blog

If you want to remove the preview button from a form in your own custom module use the following hook_form_alter method to remove the preview element from the form array.

function mymodulename_form_alter($form_id, &$form) {

    if(($form_id=="mycontenttype_node_form")||($form_id=="comment_form")) {
      unset ($form['preview']);
    }
}