var lastLeftMenu = -1;
function showLeftMenu(index, leftMenuId) {
	// hide last menu
	var i = 0;
	if (document.getElementById)
	{
		while (document.getElementById("leftMenu"+leftMenuId+i))
		{
			document.getElementById("leftMenu"+leftMenuId+i).style.display = "none";
			i++;
		}
	}
	else if (document.all)
	{
		while (document.all("leftMenu"+leftMenuId+i))
		{
			document.all("leftMenu"+leftMenuId+i).style.display = "none";
			i++;
		}
	}
	// if current menu do nothing
	if (lastLeftMenu == index)
	{
		lastLeftMenu = -1;
		return;
	}
	// display menu
	if (document.getElementById && document.getElementById("leftMenu"+leftMenuId+index))
	{
		document.getElementById("leftMenu"+leftMenuId+index).style.display = "";
	}
	else if (document.all && document.all("leftMenu"+leftMenuId+index))
	{
		document.all("leftMenu"+leftMenuId+index).style.display = "";
	}
	lastLeftMenu = index;
}