How to call this variable in VB4

[Breakpoint]

The hook is threadmanage_start

Here is the code, what I am trying to do is find all <h1> tags and replace them with nothing. But it is not working. You seem pretty smart, would you know what the main problem with my code is?

if ($_REQUEST['do'] == 'editthread' AND $threadinfo['open'] != 10) {
$page_templater['threadadmin_editthread'] = str_replace('<h1>','',$page_templater['threadadmin_editthread']);
}