Hi. I am hooking a node form. The content type has a  cck node reference field, and the form has a text field to select the node. In some cases, the user should not be allowed to select...the value should be forced. So I decide which field name to use based on the content type, and then change the text field to a hidden field like this:

        $form[$var] = array(

        '#type' => 'hidden',
        '#value' => $nid,
        );

The form comes up just fine. The problem is, when it is submitted, I receive:

Fatal error: Cannot unset string offsets in sites\all\modules\cck\content.module on line 1248

Thanks,

Jeff