[edbri871]

Open the NAVBAR template and find this code:

<a href="private.php?$session[sessionurl]">$vbphrase[private_messages]</a>

And right before it add this code:

<if condition="$bbuserinfo['pmunread']"><img src="image1" alt="Unread PMs" /><else /><img src="image2" alt="No Unread PMs" /></if>

Replace "image1" with the url to the image for if they have a pm, and image 2 to the url if they don't have a PM.

edit: btw if you want it to just have an image for unread PMs and not for if there's none then use this:

<if condition="$bbuserinfo['pmunread']"><img src="image1" alt="Unread PMs" /></if>