[kh99]

Well, you could make the "Edit" control go away by creating a plugin using hook group_messagebit_display_complete and setting $message['edit'] to false. I guess strictly speaking that doesn't stop someone from editing the message, but someone would have to be really desperate to figure out how to do it without having the control. (Or you could just use a second plugin to guard against that).

Anyway, you could do something like this:

if ($message['edit'])
{
    if ((TIMENOW - $message['dateline']) > (60 * 30))
        $message['edit'] = false;
}

but that doesn't account for admins being able to edit forever. It's easy enough to check if the current user is an admin, but what you really want is to know if they have permission to edit that discussion and that message. (The code that figures that out is in includes/class_groupmessage.php, in class vB_Group_Bit_Message, if that helps).