You added the code from the search field into a new form after the form you had there (the one with the drop-down and Show Websites). You kinda have the html all messed up around there. You only need one form - you have two (one that you can't even access). You need to add those "type=hidden" inputs to under your other hidden inputs. You also need to give your new form a unique name..... I have a search form on my torrents page and I have it set to only search thread titles in two forums. This is some of what I added in my template:
HTML Code:
<form action="search.php" method="post" name="vbform"><input type="hidden" name="s" value="$session[sessionhash]" /><input type="hidden" name="do" value="process" /><input type="hidden" name="titleonly" value="1" /><input type="hidden" name="showposts" value="0"><input type="hidden" name="sortby" value="lastpost"><input type="hidden" name="order" value="descending"><input type="hidden" name="s" value=""><input type="hidden" name="forumchoice[]" value="12"><input type="hidden" name="forumchoice[]" value="13">
All my input fields that they may select
</form>
So, you can see that I do use the search.php action and I give it a unique name. I also fill in a ton of hidden fields that the search form will need. Then, all my input fields use the correct name to correspond to what the search.php file wants.