As Brown suggested, use the USER_HASPERMISSION(security_code) function. When you setup your users, develop a scheme such that each has a particular security level (A to Z). It's easiest to use a progressive level system. In other words, the lowest user has only A, the next to the lowest, A and B, the next A, B and C, and so forth to the highest level. Then, let's say you have a button with medium security of 'C'. All users logged on greater than C would be able to use that button with the visibility attribute. Any user less than 'C' the button would disappear.