My Hover Wont Work, Help Please! Options

[tropicaltide071]

I've finally figured out how to make my xanga look nice, and now all I really want is to have a hover. I found a link that I like, but it wont work! Is there a reason for this, or is the link not working. Here it is:

<!-- begin code provided by createblog.com -->
<style type="text/css">
A:hover
{
filter: flipv
}
</style>
<!-- end code provided by createblog.com -->

Its supposed to go upside down!
Help me pleaseeeeee!