function changeDisplay(div)
{
	for (var i = 1; i<=30; i++)
	{
		if (document.getElementById('submenu'+i))
		{
			document.getElementById('submenu'+i).style.display='none';
		}
	}
	
	if (document.getElementById(div))
	{
		document.getElementById(div).style.display='block';
	}
}