Hi how to show a code always on top of the first thread?
What do you mean with on the top? If above all posts, you can simply edit showthread template, no conditionals needed. For example add your code after {$header} or above <table border="0" cellspacing="{$theme['borderwidth']}" cellpadding="{$theme['tablespace']}" class="tborder" style="clear: both; border-bottom-width: 0;">