<div id="centrar" style="text-align:center";>
<marquee HEIGHT=90px onMouseOver="stop()" onMouseOut="start()" scrollamount="3" scrolldelay="100" direction="up">
<a href="http://buscarlibros.net/" target="_blank"><img src="http://i.imgur.com/6U6sN9Z.png" width="140" height="50"  alt=""/></a>
<a href="http://imgur.com/" target="_blank"><img src="http://i.imgur.com/6GDM1Sv.png" width="140" height="50"  alt=""/></a>
<a href="http://ircap.net/" target="_blank"><img src="http://i.imgur.com/mIoncx6.png" width="140" height="50"  alt=""/></a>
</marquee>
 </div>