Tady je rozklikávací menu s cookies, takže si to po reloadu pamatuje rozkliknuté položky.

Javascript:

function ukazat_nebo_skryt(id) 
	{
	var status=document.getElementById(id);
	
	if (status.style.display != "block")
		{
		status.style.display = "block";
		setCookie(id, 1, 365);
		}
	else
		{
		status.style.display = "none";
		setCookie(id, 0, 365);
		}
	}
	
function setCookie(c_name,value,expiredays)
	{
	var exdate=new Date();

	exdate.setDate(exdate.getDate()+expiredays);

	document.cookie=c_name+ "=" +escape(value)+((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
	}

function getCookie(c_name)
	{
	if (document.cookie.length>0)
		{
		c_start=document.cookie.indexOf(c_name + "=");
		if (c_start!=-1) 
			{
			c_start=c_start + c_name.length+1;
			c_end=document.cookie.indexOf(";",c_start);
			if (c_end==-1) 
				{
				c_end=document.cookie.length;
				}
			return unescape(document.cookie.substring(c_start,c_end));
			}
		}
	return "";
	}

function beginMenu()
	{
	var i = "0";
	var foo = document.getElementById("menu").getElementsByClassName("skryte");
	for (i=0;i<foo.length;i++)
		{
		var num = i+1;
		var id = "prvek"+num;
		
		what=document.getElementById(id);

		status=getCookie(id);
		if (status!=null && status!="" && status !=0)
			{
			what.style.display="block";
			}
		else
			{
			what.style.display="none";
			}
		}
	}

window.onload=new Function("beginMenu()");

.skryte {display: none;}

 <div id="menu">
 	<div onclick="javascript:ukazat_nebo_skryt('prvek1');">Položka1</div>
	<div id="prvek1" class="skryte">
		<a href="index.php">Submenu1-1</a><br>
		<a href="index.php">Submenu1-2</a><br>
		<a href="index.php">Submenu1-3</a>
	</div>
	
	<div onclick="javascript:ukazat_nebo_skryt('prvek2');">Položka2</div>
		<div id="prvek2" class="skryte">
		<a href="index.php">Submenu2-1</a><br>
		<a href="index.php">Submenu2-2</a><br>
		<a href="index.php">Submenu2-3</a>
		</div>
	
	<div onclick="javascript:ukazat_nebo_skryt('prvek3');">Položka3</div>
		<div id="prvek3" class="skryte">
		<a href="index.php">Submenu3-1</a><br>
		<a href="index.php">Submenu3-2</a><br>
		<a href="index.php">Submenu3-3</a><br>
		</div>
</div>