function calcPrice ()
{
	var gift_price = 0.0, print_price = 0.0;
	amount = parseInt(document.forms['gift'].elements['gif_amount'].value);
	num_col = parseInt(document.forms['gift'].elements['gif_num_col'].value);

	for (i=0; i < price_list.length; i++)
	{
		if (gift_price <= 0 && amount >= price_list[i][0] && amount <= price_list[i][1])
			gift_price = price_list[i][2];
	}
	if (gift_price <= 0)	gift_price = price_list[price_list.length-1][2];

	if (num_col <= 0)
	{
		print_price = 0.0;
	}
	else
	{
		for (i=0; i < current_group.length; i++)
		{
			if (current_group[i][0] == amount)
			{
				print_price = current_group[i][1]*num_col + current_group[i][2];
			}
		}
	}

	document.forms['gift'].elements['price_uint'].value = number_format (gift_price, 2);
	document.forms['gift'].elements['price_print'].value = number_format (print_price, 2);
	document.forms['gift'].elements['price_gp'].value = number_format (gift_price+print_price, 2);
	document.forms['gift'].elements['price_all'].value = number_format ((gift_price+print_price)*amount, 2);
}

function changeGroup (gid)
{
	var key = 'grp_'+gid;
	amount = parseInt(document.forms['gift'].elements['gif_amount'].value);
	num_col = parseInt(document.forms['gift'].elements['gif_num_col'].value);

	if (group_list[key])
	{
		current_group = group_list[key];
		document.forms['gift'].elements['gif_amount'].options.length = 0;
		for (i=0; i < current_group.length; i++)
			document.forms['gift'].elements['gif_amount'].options[i] = new Option (current_group[i][0], current_group[i][0], amount==current_group[i][0] ? 1 : 0, amount==current_group[i][0] ? 1 : 0);

		current_num_col = group_color[key];
		document.forms['gift'].elements['gif_num_col'].options.length = 0;
		for (i=0; i<=current_num_col; i++)
			document.forms['gift'].elements['gif_num_col'].options[i] = new Option (i, i, num_col==i ? 1 : 0, num_col==i ? 1 : 0);
	}
	calcPrice ();
}