enforce at least one element and at most N from a set of N elements- XSD how?

• From: dave <ceek63@...>
• To: xml-dev@...
• Date: Sun, 4 Nov 2007 20:02:41 -0800 (PST)

How would I design an XSD to enforce-
  at least one element and at most 4 elements must be
present from a set of 4 elements.

sequence/choice/all with minoccurs/maxoccurs doesn't
seem to help here.

Thanks
-D

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com