function mod_cart()
{	
	elements 			= document.forms['shopping_cart'].elements;
	rem_list 			= '';
		
	for(i=0;i<elements.length;i++)
	{
		element			= elements[i]
		element_name 	= element.id;																		// name of element
		element_id		= element_name.substring(element_name.lastIndexOf('_')+1, element_name.length);		// id of element
		element_checked = element.checked;																	// if the element is checked
		
		// adds checked checkboxes to the remove list
		if(element_name.indexOf('box_') != -1 && element_checked) rem_list += element_id+',';
		
		// removes items whose quantites have been changed to 0
		if(element_name.indexOf('qty_') != -1 && element.value == 0) rem_list += element_id+',';
	}
	
	rem_list = rem_list.substring(0,rem_list.length-1);		// remove last comma
	
	if(document.getElementById('rem_list')) document.getElementById('rem_list').value = rem_list;
	
}






function ship_to_billing(checked)
{
	if(checked)
	{
		document.getElementById('shipping_first_name').value	= document.getElementById('billing_first_name').value;
		document.getElementById('shipping_last_name').value		= document.getElementById('billing_last_name').value;
		document.getElementById('shipping_address').value		= document.getElementById('billing_address').value;
		document.getElementById('shipping_address_2').value		= document.getElementById('billing_address_2').value;
		document.getElementById('shipping_city').value			= document.getElementById('billing_city').value;
		document.getElementById('shipping_state').value			= document.getElementById('billing_state').value;
		document.getElementById('shipping_zip').value			= document.getElementById('billing_zip').value;
	}
	else
	{
		document.getElementById('shipping_first_name').value	= '';
		document.getElementById('shipping_last_name').value		= '';
		document.getElementById('shipping_address').value		= '';
		document.getElementById('shipping_address_2').value		= '';
		document.getElementById('shipping_city').value			= '';
		document.getElementById('shipping_state').value			= '';
		document.getElementById('shipping_zip').value			= '';
	}
}