[xsl] Multi condition sum

["peter verhaar" <peter.verhaar1@xxxxxxxxx>]

Hello,

Assume this snippet:

<bools>
<book>
			<column name="quantity">50</column>
			<column name="status">available</column>
	</book>
		<book>
			<column name="quantity">10</column>
			<column name="status">available</column>
	</book>
		<book>
			<column name="quantity">3</column>
			<column name="status">lost</column>
	</book>
</bools>

Thanks!