[Adrian Schneider]

PHP Code:

if ($bbuserinfo[posts] >= 500)
{ 
    eval('print_output("' . fetch_template('template_name') . '");');
}
else 
{
    print_no_permission();
} 


This should work.
For username, it is just $bbuserinfo[username]. $bbuserinfo[fieldname] displays the field value of the member browsing the page. (so you can use tons of others as well).