function preloadMoreImages() {
if (document.images)
	{
	var btn_makingtools_roll = new Image
		btn_makingtools_roll.src = "images/btn_makingtools_over.gif"
	var btn_pottery_roll = new Image
		btn_pottery_roll.src = "images/btn_pottery_over.gif"
	var btn_nativecopper_roll = new Image
		btn_nativecopper_roll.src = "images/btn_nativecopper_over.gif"
	var btn_catlinite_roll = new Image
		btn_catlinite_roll.src = "images/btn_catlinite_over.gif"
	}
}