if (document.images)  {
	image1 = new Image
	image2 = new Image
	image3 = new Image
	image4 = new Image
	image5 = new Image
	image6 = new Image
	image1.src = 'images/sub1_off.gif' 
	image2.src = 'images/sub1_on.gif'
	image3.src = 'images/sub2_off.gif' 
	image4.src = 'images/sub2_on.gif' 
	image5.src = 'images/sub3_off.gif' 
	image6.src = 'images/sub3_on.gif'
}