converting vb3 MOD to vb4 MOD

[WorldDomination]

I do not currently have a VB4 forum to use as reference, so it's a bit harder for me to figure out all of the differences and stuff between vb3 and vb4. I want to convert my username images MOD to work with vb4.

This is my postbit code in vb3:

<div id="postmenu_$post[postid]">
                    <if condition="$show['profile']">
                    <a class="bigusername" href="member.php?$session[sessionurl]u=$post[userid]"><if condition="$post['field8']"><img src="$post[field8]" border="0"/></a> <else />$post[musername]</a></if>
                    $post[onlinestatus]
                    <script type="text/javascript"> vbmenu_register("postmenu_$post[postid]", true); </script>
                    <else />
                    $post[musername]
                    </if>
                </div>

All I currently know is that I need to add "vb:" to the tags such as the if/else tags. I don't know what else has really changed, I'm assuming "$post" has changed as well?

This is the username block in vb4:

<div class="username_container">
                    <vb:if condition="$post['userid']">
                        {vb:raw memberaction_dropdown}
                        {vb:raw post.onlinestatus}
                    <vb:else />
                        <span class="username guest">{vb:raw post.username}</span>
                    </vb:if>

Any help is greatly appreciated.