Ban a user based on a string contained

[JPnyc]

in the post or signature? I want to ban a user automatically, based on the presence of a particular text string contained in the post or sig. I'll code it myself (even though PHP isn't among my languages) but I need a hint 1st. Where would such a function best be placed? Which file(s)? Would it be in the showthread template ? Or New Thread/reply? Thanks for any clues.

Here's the compound if I have so far:

if (strpos($post[message], "Blah") !== false)&&(strpos($post[message], "BlahBlah")!==false)&&(!can_moderate($thread['forumid'], 'caneditthreads') && (!can_moderate($thread['forumid'], 'caneditposts'))

Is there a simpler way of testing usergroup? Something like $bbuserinfo[$usergroup] or something along those lines? Thanks for any help

Ok, I found the easier method to test for usergroup: $bbuserinfo['usergroupid']; Now what I need is the working statement. How does one change usegroup? Is it anything like

$vbulletin->userinfo['usergroupid']=8; //that?