image display determined by user group status

[dreamhost]

Originally Posted by Zachery

<if condition="!is_member_of($bbuserinfo, X)"> Img code for anyone not paying </if>
Replace X with the usergroup that is doating / paying

when i try that i get the following message:
The following template conditional expression contains function calls:

<if condition="!is_member_of($bbuserinfo, 6)">

Function Name Usage in Expression
is_member_of is_member_of($bbuserinfo, 6)

With a few exceptions, function calls are not permitted in template conditional expressions. Please go back and re-write this expression.

The following functions are allowed in template conditional expressions:
in_array() is_array() is_numeric() isset() empty() defined() array() can_moderate() can_moderate_calendar() exec_switch_bg()


I was putting that in the header template.
ideas?