function addBox()
	{
	var tr1 = document.getElementById('tr1');
	var tr2 = document.getElementById('tr2');

	var new1 = tr1.cloneNode(true);
	var new2 = tr2.cloneNode(true);

	new1.childNodes[1].childNodes[0].value = '';
	new1.childNodes[3].childNodes[0].value = '';
	new2.childNodes[1].childNodes[0].value = '';

	var bt = document.getElementById('BoxTable');
	bt.appendChild(new1);
	bt.appendChild(new2);
	}

function delBox(tr1)
	{
	if (document.getElementById('BoxTable'). rows.length > 2)
		{
		if (confirm('Are you sure you want to delete this box?'))
			{
			removeChildrenFromNode(tr1.next());
			tr1.next().removeNode();
			removeChildrenFromNode(tr1);
			tr1.removeNode();
			}
		}
	else
		{ alert('You can\'t delete the last item.'); }
	}

function removeChildrenFromNode(node)
	{
	if(node.hasChildNodes())
		{
		while(node.childNodes.length >= 1 )
			{ node.removeChild(node.firstChild); }
		}
	}