Code:
<if condition="!is_member_of($bbuserinfo, 1, 3)">
<if condition="$show['avatar']">
<a href="member.php?$session[sessionurl]u=$post[userid]">
<img src="$post[avatarurl]" alt="<phrase 1="$post[username]">$vbphrase[xs_avatar]</phrase>" width="48" height="48" border="0" /></a>
</if>
</else>
<img src="defaultavatar.gif" alt="Avatar" width="48" height="48" border="0" />
</if>