function shutter(thisDiv) { 
	
	// make a list of all the divs on the page 
	var divList = document.getElementsByTagName('div');

 	// sort out which divs are top-level shutters and which are sub-level shutters (sub*) 
	var shutterList = []; 
	var sub01shutterList = [];
	for (var i = 0; i < divList.length; i++) 
	{ 
		if (divList[i].id.substr(0,8) == 'shutter-') 
		{ 
			shutterList.push(divList[i]); 
		}
		else if (divList[i].id.substr(0,14) == 'sub01-shutter-')
		{
			sub01shutterList.push(divList[i]);
		}
	}
	
	//------------------------------------------------
	if(thisDiv.substr(0,8) == 'shutter-')
	// top-level div was clicked.
	{
		// go through all the top-level shutters and close them (except the one that just opened) 
		for (var i = 0; i < shutterList.length; i++) 
		{ 
			div = document.getElementById(shutterList[i].id); 
			// var headerdiv = document.getElementById(headerName);
			
			if (div.id == thisDiv) 
			// this is the div that's been clicked on
			{
				if (div.style.display == 'none' || div.style.display == '') 
				{ 
					div.style.display = 'block'; 
					//headerdiv.className='shutterHeader shutterHeaderOpen';
				} 
				else 
				{ 			
					div.style.display = 'none'; 
					//headerdiv.className='shutterHeader';
				}
			}
			else 
			// these are the divs that were not clicked on
			{
				div.style.display = 'none'; 
				//headerdiv.className='shutterHeader';
			}
		}
	}
	else if (thisDiv.substr(0,3) == 'sub')
	// sub-level div was clicked.
	{
		// go through all the sub-level shutters and close them (except the one that just opened) 
		for (var i = 0; i < sub01shutterList.length; i++) 
		{ 
			div = document.getElementById(sub01shutterList[i].id); 
			// var headerdiv = document.getElementById(headerName);

			if (div.id == thisDiv) 
			// this is the div that's been clicked on
			{
				if (div.style.display == 'none' || div.style.display == '') 
				{ 
					div.style.display = 'block'; 
					//headerdiv.className='shutterHeader shutterHeaderOpen';
				} 
				else 
				{ 			
					div.style.display = 'none'; 
					//headerdiv.className='shutterHeader';
				}
			}
			else 
			// these are the divs that were not clicked on
			{
				div.style.display = 'none'; 
				//headerdiv.className='shutterHeader';
			}
		}
	} 	
}