[thelist] javascript for expand/collapse list (aka tree view)

[Bill Creswell]

:I am looking for some JavaScript for an expandable/collapsible "tree view" 

I find this very easy/useful/flexible:
<!--
function blocking(nr)
{
	if (document.all)
	{
		current = (document.all[nr].style.display == 'none') ? 'block' : 'none';
		document.all[nr].style.display = current;
	}
	else if (document.getElementById)
	{
		vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'none';
		document.getElementById(nr).style.display = vista;
	}
}
// -->

<input class=topmenu type=button value="Toggle Display" 
	onclick="blocking('number2'); return false;">
	    
		<div id="number2" style='display:none'>
    			<ul>
    			<li><a href=# >Third</a></li>
    			<li><a href=# >Fourth</a></li>
    			</ul>
    		</div>