Removing code when pressing the button again.

I am looking for JS code to allows for the custom button code to be removed from the highlighted text. Currently it continues to place the custom html code every time you click the button on the same highlighted text.

Is there a mod i can do for the JS files that would allow it to remove the custom html code when i pretty the button again? Just like it does with the bold button, etc?

Thanks!

http://wordpress.org/extend/plugins/visual-editor-custom-buttons/