Thanks,
So can I replace my existing line of code:
<xsl:eval>formatNumber(parseFloat(this.selectSingleNode("SalesOrder/Total").text),"$#,###,###,###.00")</xsl:eval>
With this:
<xsl:if test="formatNumber(parseFloat(this.selectSingleNode("SalesOrder/Total").text),"$#,###,###,###.00")"></xsl:if>