function dropdownMenu(menuID, toppos)
{
	document.getElementById('dropdown'+menuID).style.display = 'block';
	// wrapper1 is the id of the main Div; because the page is centered this is used to work out how far in the page is (+ 59px margin)
	maintableLeft = document.getElementById('wrapper1').offsetLeft + 59 ;
	document.getElementById('dropdown'+menuID).style.left = maintableLeft + document.getElementById('td'+menuID).offsetLeft + 'px';
//	document.getElementById('dropdown'+menuID).style.left = document.getElementById('td'+menuID).offsetLeft + 'px' ;
	document.getElementById('dropdown'+menuID).style.top = toppos + 'px';
}
function dropupMenu(menuID)
{
	document.getElementById('dropdown'+menuID).style.display = 'none';	
}

function displayImage(imgURL, imgID)
{
	document.getElementById(imgID).src = imgURL;
}