[MrNase]

Well, that did the trick. I deleted that and replaced it with $show[onfrontpage] and that didn't work
Thanks alot

my next problem:

i added the following to the SHOWTHREAD-template

 <div><label for="cb_onfrontpage"><input type="checkbox" name="do" value="onfrontpage" id="cb_onfrontpage" tabindex="1" $checked[onfrontpage] />Auf der Startseite?</label></div>

and the following to options.php:

 // ############################### start do set on frontpage ###############################
 if ($_POST['do'] == 'onfrontpage')
 {
 	$DB_site->query("UPDATE " . TABLE_PREFIX . "thread SET onfrontpage = $threadinfo[onfrontpage] WHERE threadid = $threadid");
 
 	$_REQUEST['forceredirect'] = 1;
 	$url = "showthread.php?$session[sessionurl]t=$threadid";
 	eval(print_standard_redirect('redirect_openclose'));
 
 }

But it doesn't change the value in the database

If i change $threadinfo[onfrontpage] to '1' or '0' manually he'll change it in the database... wrong variable i try to use?