How to not make a pop up scroll the window down using css3

How to not make a pop up scroll the window down using css3

I'm working on a pop up code right now... This is what I have so far
http://jsfiddle.net/3EuZM/
<a href="#pop2">Pop-up Two</a>
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<div id="pop2" class="pop-up">
<div class="popBox">
<div class="popScroll">
<h2>Pop-up Two</h2>
<div class="article-image"><img src="images/slow-moving-stock.png"></div>
<div class="article-word">autem</div>
<div class="article-def">Nam a justo vulputate, interdum quam
nec, auctor turpis. Nulla dapibus, lectus a aliquet lacinia,
turpis dui feugiat dolor</div>
<div class="article-samp">Donec faucibus pulvinar magna, vel
convallis ipsum interdum at.</div>
</div>
<a href="" class="close"><img src="images/close.png" width="20px" ></a>
</div>
<a href="#links" class="lightbox">Back to links</a>
</div>
Now, you see... when I click on the link and the pop-up appears, the whole
window scrolls down to the bottom of the page :( I don't know how to stop
this. any ideas?
*note, i added the
to empasize the scrolling down...