window.onload=rollup;

function rollout(objMenuitem)
{
    if (objMenuitem.parentNode.lastChild.style.display == 'block')
	{
        objMenuitem.parentNode.lastChild.style.display = 'none';
		
		objMenuitem.lastChild.setAttribute('src', 'images/grey_plus.gif');
	}

    else
	{
        objMenuitem.parentNode.lastChild.style.display = 'block';
		
		objMenuitem.lastChild.setAttribute('src', 'images/grey_minus.gif');
	}
		
    // Stop the browser requesting the link
    return false;
}

function rollup()
{
    var bRollup, objLinks, objNode, objAnchor;

    // Check we're working with a DOM compliant browser
    if (document.getElementById && document.createElement)
    {
        
		//var strLocation = window.location;

		var objMenu = document.getElementById('collapse_nav');

        var objNested = objMenu.getElementsByTagName('ul');

		var objImage = objMenu.getElementsByTagName('img');

        // Hide each of the nested unordered list
        for (var i=0; i<objNested.length; i++)
        {

			objNested[i].style.display = 'none';

			for (var j=0; j<objImage.length; j++)
			{	
				objAnchor = objImage[j].parentNode;
				
				objAnchor.onclick = function(){return rollout(this);}
			}
			
        }
    }
}