Postbit (legacy) SNS links

[YouBabble]

Hey there. When using vBulletin 3.8, in my postbit I had icons with a link to the users' YouTube account like so:

<vb:if condition="is_member_of($bbuserinfo, 6, 7, 9)">
<vb:if condition="$post['field5']">
<dt>YouTube</dt>
<dd><a href="http://youtube.com/user/$post['field5']">
<img alt="YouTube" border="0" src="images/icons/youtube.png" /></a></dd>
</vb:if></vb:if>

Now I have changed it so it shows the icon if a user has filled in the YouTube account profile information bit. What isn't working is the anchor hyperlink directing the user to the YouTube account. What I mean is the old method of using "$post['field5']" to echo the username isn't working.

What is the new way to echo the username into the anchor so it can direct to the YouTube account. Sorry for the poor explanation, but ask questions if needed.

Thanks!