Simple JavaScript Image Rollover Effect Code;  Movel Your Cursor Over Image Below.

<!-- Begin www.DesignerWiz.com Image Rollover --><a href="http://www.snapbuilder.com" onMouseOver='rollover.src="Your 1st Image"' onMouseOut='rollover.src="Your 2nd Image"'><img src="Your 2nd Image" name="rollover" border="0" width="0" height="0" alt="Description Of Image Here"></a><!-- End Image Rollover -->

Simply Cut and Paste Mouse Over code
Be sure to properly place script position in body of html where wanted viewed
Change URL & Images, image sizes to match yours
It is advised to use a preload image script for hidden rollover picture to have instant preview ability by preloading the image before rollover image is needed at load time

This script has been in the DesignerWiz.com Public Library.