myPix = new Array("images/leaf4.jpg","images/head4.jpg","images/mtn4.jpg","images/sun4.jpg")
imgCt = myPix.length

function header() {
	if(document.images) {
		randomNum = Math.floor((Math.random() * imgCt))
		document.myPicture.src = myPix[randomNum]
		}
	}