var last = "";

function toggle(main){
	if (main.style.display == "none"){
		if (last == ""){
			main.style.display = "";
		}
		else{
			last.style.display = "none";
			main.style.display  = "";
		}
	}
	else{
		main.style.display = "none";
	}
last = main;
}