Need to check security for dropdown

When I bind the disabled property on a dropdown with the isInRole for security it disables the control when a user is in the associated group. I need this to be the opposite functionality but I do not see a isNotInRole method. Is there a way to do this so all users are disabled unless they are members of the required group?

Did you try something like ${security.isInRole("Admin") == false} ? It is the equivalent of having a method isNotInRole.