if (document.images) {
	image1on = new Image();
	image1on.src = "img/home_2.gif";
	image2on = new Image();
	image2on.src = "img/about_2.gif";
	image3on = new Image();
	image3on.src = "img/practice_2.gif";
	image4on = new Image();
	image4on.src = "img/contact_2.gif";
	image1off = new Image();
	image1off.src = "img/home_1.gif";
	image2off = new Image();
	image2off.src = "img/about_1.gif";
	image3off = new Image();
	image3off.src = "img/practice_1.gif";
	image4off = new Image();
	image4off.src = "img/contact_1.gif";
	image1active = new Image();
	image1active.src = "img/home_3.gif";
	image2active = new Image();
	image2active.src = "img/about_3.gif";
	image3active = new Image();
	image3active.src = "img/practice_3.gif";
	image4active = new Image();
	image4active.src = "img/contact_3.gif";
	}
	
	function changeImages() {
		if (document.images) {
		  for (var i=0; i<changeImages.arguments.length; i+=2) {
		    document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
		  }
		}
	}