var lastobject="";


function visible(object,state){
	var status
	if (state)
		status = "visible";
	else
		status = "hidden";
		

	if (document.layers)
			document.layers[object].visibility = status;
		else if (document.all)
			document.all[object].style.visibility = status;
		else if (document.getElementById)
			document.getElementById(object).style.visibility = status;
}

function ShowMenu(objName){

	if (lastobject != ""){
	HideMenu(lastobject)
	
	}
	visible(objName,true);
			
	lastobject = objName;
	
}

function HideMenu(objName){
    
	if (lastobject != ""){
	visible(objName,false);
	}
	
}