After "X" click on thanks button the next Popup window

[dxflw]

I have added this popup code to my thanks button template.

<if condition="$show['post_thanks_postbtn']">
<a href="showthread.php?$session[sessionurl]thanks_mode=add&amp;postid={$postid}"
 onclick="window.open('http://www.somesite.com/')";return false;>
<img src="$stylevar[imgdir_button]/thanks.gif" alt="$vbphrase[say_thank_you]"
 title="$vbphrase[say_thank_you]" border="0" /></a> </if>

And every time if the user clicks to the thanks buttons they shows a avertise site.
Now i wan't to change that like this:
If a member clicks the thanks button and its shows the popup window then the next popup window must opens after 10 clicks or after 15 minutes.
(10 clicks or after 15 minutes is example, i want to set manual higher or lower)

Any idea how do i that?