Calculations involving measurements with units

Hello,

I am using a parameter called 'page-height', set to, say, '297mm' for
an A4 page.  I have a particular margin I want to set to '$page-height
/ 3.75'---what is the best way to strip the trailing 'mm' prior to the
calculation and append it again to the result?  My first attempt was
to start with a variable:

<xsl:variable name="upper-margin" select="number($page-height) / 3.75"/>

and then open the fo:block with:

<fo:block text-align="center" margin-top="$upper-margin">

The XPath in the xsl:variable element above is apparently invalid.  I
also need to append the 'mm' prior to using the variable in the
fo:block.  What is the best approach here?


-- 
Paul.

mailto:paulh@xxxxxxxxxxxxxx
mailto:phoadley@xxxxxxxxxxxxxxxxxxxxx

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