change the menu item image when viewing a page

Hi all,

My problem is: I am currently using the menuclass module to assign class names to each of my menuitems, which works great for me to be able to assign the menu item to be an image, and also to set a different image when I hover over the item.
However, now I need to be able to change the menu item image to a different image when the item is clicked and the page is being viewed. There is no specific behavior defined like active or hover, so I'm assuming I need to work around this a different way. Normally, using javascript, I could easily use the onclick property and deal with this. However, I'm not sure what to do here.
Any help would be highly appreciated.

Thank you