if(document.images){
		caseStudy1On= new Image(130, 90);
		caseStudy1On.src="images/caseStudy1Over.png";
		caseStudy1Off= new Image(130, 90);
		caseStudy1Off.src="images/caseStudy1.png";

		caseStudy2On= new Image(130, 90);
		caseStudy2On.src="images/caseStudy2Over.png";
		caseStudy2Off= new Image(130, 90);
		caseStudy2Off.src="images/caseStudy2.png";

		caseStudy3On= new Image(130, 90);
		caseStudy3On.src="images/caseStudy3Over.png";
		caseStudy3Off= new Image(130, 90);
		caseStudy3Off.src="images/caseStudy3.png";

		caseStudy4On= new Image(130, 90);
		caseStudy4On.src="images/caseStudy4Over.png";
		caseStudy4Off= new Image(130, 90);
		caseStudy4Off.src="images/caseStudy4.png";

	}

	function buttonOn(imgName)
	{
		if(document.images){
			imgOn = eval(imgName + "On.src");
			document[imgName].src = imgOn;
		}
	}

	function buttonOff(imgName)
	{
		if(document.images){
			imgOff = eval(imgName + "Off.src");
			document[imgName].src = imgOff;
		}
	}