var navState = "off"

		
function	swap(imgName)	{
					if (navState == "off"){
					eval("document.images." + imgName + ".src = 'images/button_" + imgName + "-on.gif'");
					navState = "on"
					}
					
					else	{
					eval("document.images." + imgName + ".src = 'images/button_" + imgName + "-off.gif'");
					navState = "off"
					}
				}