UBB.threads PHP Forum Software Community Forums UBB.threads 7 Version 7 Support how to detect first page on thread mode

i want to add fb like button only displayed on the first page of thread

i'm using this code on showflat.tpl

{if $page==1}
fblike code here
{/if}

this code succes to get $page while we are on login mode, but if we doesn't login $page is empty

i'm still confused, cause in my localhost, $page always have any value