function changeTab(tabNum) {
		var numLayers = 4;	//number of layers in the tab area
		var tabID = "tab-area-tab"	//tab CSS ID without number suffix
		var layerID = "tab-area-layer"	//layer CSS ID without number suffix

		for (var i = 1; i <= numLayers; i++) {
			if (i != tabNum) {
				var curLayer = layerID + i;
				document.getElementById(curLayer).style.display="none";
				var curTab = tabID + i;
				document.getElementById(curTab).className="";
			}
		}
		var showLayer = layerID + tabNum;
		document.getElementById(showLayer).style.display="block";
		var showTab = tabID + tabNum;
		document.getElementById(showTab).className="tab-area-highlighted";
		document.getElementById(showTab).blur;
	}