Is this the problem?
PHP Code:
<input type=\"button\" class=\"button\" name=\"warn\" value=\"Warn $post[username] (non-post related)\" accesskey=\"w\" onClick=\"window.location='../Warn.php?$session[sessionurl]do=WarnUserNoPost&return=user&id=$userid'\"></a>
it need to be
PHP Code:
<input type=\"button\" class=\"button\" name=\"warn\" value=\"Warn $post[username] (non-post related)\" accesskey=\"w\" onClick=\"window.location='../Warn.php?$session[sessionurl]do=WarnUserNoPost&return=user&id=$user[userid]'\"></a>