xsl:when test access the XML

I'm trying to use the following but when the node G_MAIN/JRNL_CURRENCY_CODE in the XML is 'STAT' the expression does not evaluate to true. 

<xsl:variable name="fm"><xsl:choose><xsl:when test="G_MAIN/JRNL_CURRENCY_CODE='STAT'"><xsl:vallue-of select="'999G990D99999'"/></xsl:when><xsl:otherwise><xsl:value-of select="'999G990D99'"/></xsl:otherwise></xsl:choose></xsl:variable>