override comment-or-uncomment-region gives an error

[ishi soichi]

I am trying to override the existing function,
comment-or-uncommnent-region like

(defun comment-or-uncomment-region ()
  (interactive)
  (cond ((equal major-mode 'web-mode)
 (web-mode-comment-or-uncomment))
(t
 (comment-or-uncomment-region))))

When using web-mode, the commenting function is different. So I need
something like this.

It works for web-mode case, but it raises an error for any other modes,

  cond: Lisp nesting exceeds `max-lisp-eval-depth'

Does anyone see why?

soichi