[MarkFL]

When you use the is_member_of() function, you typically need to pass 2 arrays as parameters, the first should contain the usergroup information of the user in question, and the second array is a list of usergroupids you are checking for.

So, for example suppose you have the userid of the user in question (in $userid), what you could then use as a condition is:

is_member_of(fetch_userinfo($userid), array(X, Y, Z))

which will return true if the user with $userid as their userid is a member of any of the usergroups with usergroupid X, Y, or Z.