CSS positioning issue with buysellads css code

Question

Having issues with formatting my buysellads onto my wordpress theme below is the css code:

![alt text][1]
display:block;font-size:11px;color:#888;font-family:verdana,sans-serif;margin:3px 40px 10px 10px;text-align:center;text-decoration:none;overflow:hidden;float:center;float:left;

I need it to vertically align as seen on cssremix.com...thanks guys