function light(element) {
	var source = element.src;
	var extensionPosition = source.lastIndexOf('.');
	var slashPosition = source.lastIndexOf('/');
	var rawFilename = source.substring(slashPosition + 1, extensionPosition);
	var extension = source.substring(extensionPosition);
	element.src = "images/buttons/"+rawFilename+'_lit'+extension;
}

function dim(element) {
	var source = element.src;
	var extensionPosition = source.lastIndexOf('.');
	var slashPosition = source.lastIndexOf('/');
	var rawFilename = source.substring(slashPosition + 1, extensionPosition);
	var extension = source.substring(extensionPosition);
	rawFilename = rawFilename.substring(0, rawFilename.length-4);
	element.src = "images/buttons/"+rawFilename+extension;
}