hi i'm trying to fill out the Tax-summary node in my invoice document
but i've stuck...
any help will be great...



my xml:
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 <ns0:Document-Invoice xmlns:ns0="http://Schemas.Invoice">
	<Invoice-Lines>
		<Line>
			<Line-Item>
				<LineNumber>1</LineNumber>
				<BuyerItemCode>MadNumber</BuyerItemCode>
				<EAN>12345678</EAN>
				<SupplierItemCode>OOP13</SupplierItemCode>
				<ItemDesctription>Orange 0,5L</ItemDesctription>
				<ItemType>CU</ItemType>
				<InvoiceQuantity>7.000</InvoiceQuantity>
				<UnitOfMeasure>SZ</UnitOfMeasure>
				<InvoiceUnitNetPrice>5.57</InvoiceUnitNetPrice>
				<TaxRate>22.00</TaxRate>
				<TaxCategoryCode>S</TaxCategoryCode>
				<TaxReference>
					<ReferenceType>PKWiU</ReferenceType>
					<ReferenceNumber>15.91.10-65.40</ReferenceNumber>
				</TaxReference>
				<TaxAmount>8.58</TaxAmount>
				<NetAmount>38.99</NetAmount>
				<Line-Order>
					<BuyerOrderNumber>5000426</BuyerOrderNumber>
					<BuyerOrderDate>2006-05-30</BuyerOrderDate>
				</Line-Order>
				<Line-Reference>
					<InvoiceReferenceNumber></InvoiceReferenceNumber>
				</Line-Reference>
				<Line-Delivery>
					<DeliveryLocationNumber>30000</DeliveryLocationNumber>
					<DeliveryDate></DeliveryDate>
					<DespatchNumber>0</DespatchNumber>
				</Line-Delivery>
			</Line-Item>
		</Line>
		<Line>
			<Line-Item>
				<LineNumber>2</LineNumber>
				<BuyerItemCode>OtherMadNumber</BuyerItemCode>
				<EAN>87654321</EAN>
				<SupplierItemCode>OOP12</SupplierItemCode>
				<ItemDesctription>Orange 1,5L</ItemDesctription>
				<ItemType>CU</ItemType>
				<InvoiceQuantity>7.000</InvoiceQuantity>
				<UnitOfMeasure>SZ</UnitOfMeasure>
				<InvoiceUnitNetPrice>5.57</InvoiceUnitNetPrice>
				<TaxRate>0.00</TaxRate>
				<TaxCategoryCode>E</TaxCategoryCode>
				<TaxReference>
					<ReferenceType>PKWiU</ReferenceType>
					<ReferenceNumber>15.91.10-65.40</ReferenceNumber>
				</TaxReference>
				<TaxAmount>0</TaxAmount>
				<NetAmount>38.99</NetAmount>
				<Line-Order>
					<BuyerOrderNumber>5000426</BuyerOrderNumber>
					<BuyerOrderDate>2006-05-30</BuyerOrderDate>
				</Line-Order>
				<Line-Reference>
					<InvoiceReferenceNumber></InvoiceReferenceNumber>
				</Line-Reference>
				<Line-Delivery>
					<DeliveryLocationNumber>30000</DeliveryLocationNumber>
					<DeliveryDate></DeliveryDate>
					<DespatchNumber>0</DespatchNumber>
				</Line-Delivery>
			</Line-Item>
		</Line>
	</Invoice-Lines>
	<Invoice-Summary>
		<TotalLines>2</TotalLines>
		<TotalNetAmount>77.84</TotalNetAmount>
		<TotalTaxAmount>8.58</TotalTaxAmount>
		<TotalGrossAmount>86.39</TotalGrossAmount>
		<Tax-Summary>
			<Tax-Summary-Line>
				<TaxRate></TaxRate>
				<TaxCategoryCode></TaxCategoryCode>
				<TaxAmount></TaxAmount>
				<TaxableAmount></TaxableAmount>
				<GrossAmount></GrossAmount>
			</Tax-Summary-Line>
		</Tax-Summary>
	</Invoice-Summary>
</ns0:Document-Invoice>

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////

I do need to group it by two elements:

<TaxRate></TaxRate>
<TaxCategoryCode></TaxCategoryCode>

after that have to get two elements

			<TaxAmount></TaxAmount>
			<NetAmount></NetAmount>

and put them summed up into
				<TaxAmount></TaxAmount>
				<TaxableAmount></TaxableAmount>

finally i'd like to achieve the following schema filled with correct
values

			<Tax-Summary-Line>
				<TaxRate></TaxRate>
				<TaxCategoryCode></TaxCategoryCode>
				<TaxAmount></TaxAmount>
				<TaxableAmount></TaxableAmount>
				<GrossAmount></GrossAmount>
			</Tax-Summary-Line>








for any help how to do it i'll be VEEEEEEERY gratefull :]

thanks in advance