Problem with Footer Links

Hello I’m having a problem with the links on my footer. I have added shopping buttons on my footer (amazon, barnes and noble etc…) and yet the only one that works is the first one which is amazon. All the other links add my url before the link (www.simplyskyy.com/lutishiawp/www.borders.com) Can someone please help me understand how to fix this. Again the only one that doesn’t do that is amazon even though they are all set up the exact same way. Here is my code.

<div id="links">
<center><a href="http://www.amazon.com" target="_blank"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/amazon.jpg"></a><a href="www.booksamillion.com" target="_blank"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/booksmill.jpg"></a><a href="www.barnesandnoble.com" target="_blank"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/barnesnoble.jpg"></a><a href="www.blackexpressions.com" target="_blank"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/blackexpression.jpg"></a><a href="www.target.com" target="_parent"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/target.jpg"></a><a href="www.walmart.com" target="_blank"><img src="http://simplyskyy.com/lutishiawp/wp-content/uploads/2010/12/walmart.jpg"></a>
  </center>>

</div>