[xsl] match multiple values for an attribute

[Jeff Sese <jsese@xxxxxxxxxxxx>]

I have an xml with elements like these:

<par @style="font-family: some.font.name; some.more.string">some text</par>

and i have an variable in my xsl file like this:

<xsl:variable name="fonts" as="xs:string+" select="('font1','font2')"/>

i want to match the text nodes that are child of an element with a style 
attribute that matches any of the fonts in $fonts. What is the xpath 
expression that can do that?

Thanks,
-- Jeff