myPix = new Array("/_img/header_xrays.jpg","/_img/header_dog.jpg","/_img/header_steth.jpg","/_img/header_cat.jpg","/_img/header_veterinarian-dog.jpg")
imgCt = myPix.length 

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