Replacement

From: bladelock (bladelock_at_discussions.microsoft.com)
Date: 07/30/04 

Date: Fri, 30 Jul 2004 12:17:01 -0700

I have one table with "00-00" in the field. How can I replace this character with "0000" there are about 20000 recordsand all different numbers (12-23, 33-24, etc). I want to take away the "-". Thanks all