[Scathefire]

Ok, I had to change a little from the above example:

<if condition="is_member_of($post, 17) OR is_member_of($post, 18) OR is_member_of($post, 6)">
<if condition="$post[field7] != ''">
<a class="smallfont" target="_blank" href="http://url.com?address=$post[field7]">Linky</a>
<else />
<a class="smallfont" target="_blank" href="http://url.com?address=$post[username]">Linky</a>
</if>
</if>

Thanks for the assistance, it is working perfectly now.