New to XSL - invalid token error

Hello everybody, 

I'm rather new to XSL and was plugging along famously until I hit  a brick
wall with the following template.

    <xsl:template match = "link[(_at_)newwin]">
        <a href = {(_at_)href}>
            <xsl:value-of select="link"/>
        </a>
        <xsl:apply-templates/>

    </xsl:template>

I am receiving "XML parse error 4: invalid token" on the <a href ..>
line(using Sablotron).  I went through all the resources I could find on
attributes and everything seems peachy keen.  If someone could point out my
error, I'd be very grateful.

Sorry if this is something that has been hashed over.

Thanks in advance, 
Anode


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