[Zope] ZPT : prevent unauthorized error

<img src="icon" tal:attributes="src item1/icon; alt item1/title_or_id"> Produce the following Error Type: Undefined Error Value: "You are not authorized to access icon." not found in "item1/icon" How could I prevent this happen? Or to provide an default icon instead? In a more general case, how could I prevent unauthorized error in ZPT? Rgs Kent Sin __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger http://phonecard.yahoo.com/