adverts after first post and X posts

[webinterface]

Hello guys,

I tried adding this to my postbit_legacy:

PHP Code:

<vb:literal>
<!-- Adverts Begin -->
<vb:if condition="($post[postcount] == '1')">
<li class="postbitlegacy postbitim postcontainer">
<div class="posthead"><span class="postdate">Google Anzeige</span></div>
<div class="postdetails">
        <div class="userinfo">
                   <div class="username_container">
                   <span class="usertitle" style="text-align:center;padding:10px; margin-top:10px;"><b>Adverts</b></span>
        <hr />
                   </div>          
                  </div>     

<div class="postbody">

---Adsense here---

<div class="cleardiv"></div></div>
<div class="postfoot"><div class="textcontrols floatcontainer"></div></div><hr />
</li>
</vb:if>
<!-- Adverts End -->
</vb:literal> 


(It has to look like a post)


I searched and found some good topics but the syntax of vb:if maybe were changed.
The Problem is now after every post in my thread there is a "adverts"-post.

Anybody can help me with this?