//universally change an image on mouseover
$(document).ready(function()
{
	$(".img_changeable").hover(
		function() //mousein
		{
			var new_src = $(this).attr('src').replace(".png", "-on.png");
			$(this).attr('src', new_src);
		},
		function() //mouseout
		{
			var new_src = $(this).attr('src').replace("-on.png", ".png");
			$(this).attr('src', new_src);
		}
	);
});