function hide( elem ) 
{
	var item = document.getElementById(elem);
	if (item)
	{
		item.style.display = 'none';
	}
}
function show( elem )
{
	var item = document.getElementById(elem);
	if (item)
	{
		item.style.display = '';
	}
}

function select_li( A_elem )
{
	// how to use:
	// <ul><li><a ... onclick="select_li(this);">...</a><li>...</ul>
	// it is going to set LI.selected and reset all the other LIs
	var LIs = A_elem.parentNode.parentNode.childNodes;
	for(var i = 0; i < LIs.length; i++) //(var i in LIs)
	{
		if(LIs[i].tagName == 'LI')
		{
			myClassname = LIs[i].className;
			LIs[i].className = myClassname.replace(/selected/, '');
		}
	}
	myClassname = A_elem.parentNode.className;
	A_elem.parentNode.className = myClassname + ' selected';
}