display $post[postid] in showthread template

[Ghostt]

hello,
i want to include a additional report link like that one in postbit:
report.php?$session[sessionurl]p=$post[postid]
the problem is that the id isnt display.
whi is this parameter not working $post[postid] in showthread template?
how to get the postid from first post ?

--------------- Added [DATE]1311196460[/DATE] at [TIME]1311196460[/TIME] ---------------

ok found it. its: $threadinfo[firstpostid]