function addClassName(oElm, strClassName){
	var strCurrentClass = oElm.className;
	if(!new RegExp(strClassName, "i").test(strCurrentClass)){
		oElm.className = strCurrentClass + ((strCurrentClass.length > 0)? " " : "") + strClassName;
		}
	}
function removeClassName(oElm, strClassName){
	var oClassToRemove = new RegExp((strClassName + "\s?"), "i");
	oElm.className = oElm.className.replace(oClassToRemove, "").replace(/^\s?|\s?$/g, "");
	}

function toggleLayer(whichLayer){
	if((whichLayer=="national")&&($("national")))
		{
			$("international").style.display = "none";
			addClassName($("internationalswitch"), "unselected");
			removeClassName($("nationalswitch"), "unselected");
			$("national").style.display = "";
		}
	if((whichLayer=="international")&&($("international")))
		{
			$("national").style.display = "none";
			addClassName($("nationalswitch"), "unselected");
			removeClassName($("internationalswitch"), "unselected");
			$("international").style.display = "";
		}

	}

toggleLayer("national");