Custom XSLT – syntax problem

Hello,

I’m new at both BizTalk and XSLT. I think it’s a syntax problem I’m having with a custom XSLT. In the script below I make a DBLookup to a table “tblPurchaseOrder” in a SQL Database for several field values. Next I have <xsl:if test="($var:vInternalFlg)"> to test one of these values (which has boolean datatype) to determine whether an XML record should be produced. Unfortunately no matter whether this field value is true or false an XML record is produced. When I change the test to

<xsl:if test="not($var:vInternalFlg) and not($var:vRAFlg)" >

No XML record is produced – even when the field values for $var:vInternalFlg & $var:vRAFlg are both false.

  <xsl:output indent="yes" omit-xml-declaration="yes" method="xml" version="1.0" />

  <xsl:template match="/">

    <xsl:apply-templates select="/s0:IMFile" />

  </xsl:template>

  <xsl:template match="/s0:IMFile">

    <ns0:APSFile>

          <xsl:for-each select="//Invoice/InvoiceHeader">

                    <xsl:if test="not(FreightAmt='')">

                              <xsl:variable name="var:v8" select="string(BCSPONo/text())" />

                              <xsl:variable name="var:v6" select="ScriptNS0:DBLookup(0 , string(BCSPONo/text()) , 'Provider=SQLOLEDB;Server=npvm02;Database=BCS_ProcurementDB;Integrated Security=SSPI;' , 'tblPurchaseOrder' , 'BCSOrderID')" />

                              <xsl:variable name="var:v7" select="ScriptNS0:DBValueExtract(string($var:v6) , 'ClientRef')" />

                        <xsl:variable name="var:vMatterID" select="ScriptNS0:DBValueExtract(string($var:v6) ,'MatterID')" />

                            <xsl:variable name="var:vInternalFlg" select="ScriptNS0:DBValueExtract(string($var:v6) ,'InternalFlg')" />

                            <xsl:variable name="var:vRAFlg" select="ScriptNS0:DBValueExtract(string($var:v6) ,'RAFlg')" />

                            <xsl:variable name="var:vErrMsg" select="ScriptNS0:DBErrorExtract(string($var:v6))" />

                            <xsl:if test="($var:vInternalFlg)">

                                          <Record>

                                 <IMInvoice>

                                      <xsl:value-of select="IMInvoiceNo/text()" />

                                </IMInvoice>

                                    <LineNO>

                                      <xsl:text>0</xsl:text>

                                    </LineNO>

etc

Any help and/or where I can learn this syntax would be much appreciated.

Cheers

Stable