var current;

function hideCurrent(){
	if(current == null)
		return;

	current.style.display="none";
}

function resetCurrent(newCurrent){
	if(newCurrent == null)
		return;

	current = newCurrent;
}

function showNew(choice){
	if(current == choice)
		return;

	hideCurrent();
	resetCurrent(choice);
	choice.style.display="";
}