Option to select an import statement

[Xmplar <info@xmplar.biz>]

In a customised stylesheet, I have two options to import a chunking stylesheet for HTML chunking:

    <xsl:import href="" class="moz-txt-link-rfc2396E" href="file:///c:/DocBook_xslns1-76/xhtml-1_1/onechunk.xsl">"file:///c:/DocBook_xslns1-76/xhtml-1_1/onechunk.xsl" />
    <xsl:import href="" class="moz-txt-link-rfc2396E" href="file:///c:/DocBook_xslns1-76/xhtml-1_1/chunkfast.xsl">"file:///c:/DocBook_xslns1-76/xhtml-1_1/chunkfast.xsl" />

How can I give users the option of selecting one import statement or the other, by using some sort of selection variable?
I know I can comment out either import statement, but is there a slicker way to do this with a simple "1" or "0" selection?

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Dave Gardiner