function hideLayer(whichLayer) {
			if (document.getElementById) {
			// this is the way the standards work
			document.getElementById(whichLayer).style.display = "none";
			}
			else if (document.all) {
				// this is the way old msie versions work
				document.all[whichlayer].style.display = "none";
			}
			else if (document.layers) {
				// this is the way nn4 works
				document.layers[whichLayer].display = "none";
			}
		}
		
		function showLayer(whichLayer) {
			if (document.getElementById) {
			// this is the way the standards work
			document.getElementById(whichLayer).style.display = "block";
			}
			else if (document.all) {
				// this is the way old msie versions work
				document.all[whichlayer].style.display = "block";
			}
			else if (document.layers) {
				// this is the way nn4 works
				document.layers[whichLayer].display = "block";
			}
		}
		
		function handleClick(whichClick) {
			if (whichClick == "hide it") {
				// then the user wants to hide the layer
				hideLayer("boxthing");			
			}
			else if (whichClick == "show it") {
				// then the user wants to show the layer
				showLayer("boxthing");
			}
		}
		
		function showActions() {
			showLayer('actions');
			hideLayer('impact');
			hideLayer('implications');
			hideLayer('challenge');
		}
		
		function showImpact() {
			hideLayer('actions');
			showLayer('impact');
			hideLayer('implications');
			hideLayer('challenge');
		}
	
		function showImplications() {
			hideLayer('actions');
			hideLayer('impact');
			showLayer('implications');
			hideLayer('challenge');
		}
	
		function showChallenge() {
			hideLayer('actions');
			hideLayer('impact');
			hideLayer('implications');
			showLayer('challenge');
		}
	
			
		function newImage(arg) {
			if (document.images) {
				rslt = new Image();
				rslt.src = arg;
				return rslt;
			}
		}
		
		function changeImages() {			
			if (document.images && (preloadFlag == true)) {
				for (var i=0; i<changeImages.arguments.length; i+=2) {
					document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
				}
			}
		}
		
	
		var preloadFlag = false;
		function preloadImages() {
			if (document.images) {
				work_actions = newImage("images/work-actions.gif");
				work_impact = newImage("images/work-impact.gif");
				work_implications = newImage("images/work-implications.gif");
				work_challenge = newImage("images/work-challenge.gif");
				work1_icon = newImage("images/work1-over.gif");
				work2_icon = newImage("images/work2-over.gif");
				work3_icon = newImage("images/work3-over.gif");
				work4_icon = newImage("images/work4-over.gif");
				work5_icon = newImage("images/work5-over.gif");
				preloadFlag = true;
			}
		}