if (document.images) {
     button1 = new Image
     button2 = new Image
     button1.src = 'common/images/home_up.gif'
     button2.src = 'common/images/home_dwn.gif'
	button3 = new Image
	button4 = new Image
	button3.src = 'common/images/email_up.gif'
	button4.src = 'common/images/email_dwn.gif'
 }