Header customization for page number

How do I print page numbers on the top right corner in PDF?

I currently have the following the header customization,

<xsl:template name="head.sep.rule">
    <xsl:attribute name="border-bottom-width">2pt</xsl:attribute>

    <xsl:attribute name="border-bottom-style">solid</xsl:attribute>
    <xsl:attribute name="border-bottom-color">black</xsl:attribute>
</xsl:template>

Josh