function unitPrice(id){
	var price = document.getElementById('priceSpan'+id).innerHTML;	
	var size = price.length;	
	var newprice = price.substring(1,size);	
	var packsize = document.getElementById('packsize').innerHTML;	
	var overall = (newprice/packsize);
	/*
	alert('price: '+price);
	alert('Length: '+size);
	alert('newprice: '+newprice);
	alert('packsize: '+packsize);
	alert('overall: '+overall.toFixed(2));
	*/

	document.getElementById('unit_price_holder1').style.display = 'inline';
	document.getElementById('unit_price_holder2').style.display = 'inline';
	document.getElementById('unit_price_holder2').innerHTML = '£'+overall.toFixed(2);
	return false;
}