arrNodes = new Array('img/menu_pic_plus.gif', 'img/menu_pic_minus.gif');
arrAlt = new Array('(+)', '(-)');
arrDisplay = new Array('ul-hidden', 'ul-visible');

function node_click(obj, id)
{
	ul_obj = document.getElementById('ul-id-'+id);
	
	intEvent = (ul_obj.className == 'ul-hidden') ? 1 : 0;
	
	ul_obj.className = arrDisplay[intEvent];
	obj.src = arrNodes[intEvent];
	obj.alt = arrAlt[intEvent];
	
	return false;
}