Find a Range of values and use starts with xsl - xslt

Question

I need to ask if Range of Supplier_ID between 985000 and 989999 then set in tag AllocationNumber the value 'FX' else let it empty.
I thought to solve it with the starts with xsl function.
But it does not work (I'm new in XSL)
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:user="http://www.altova.com/MapForce/UDF/user" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:fn="http://www.w3.org/2005/xpath-functions" exclude-result-prefixes="user xs fn user">
<xsl:output method="xml" encoding="UTF-8" indent="yes"/>
<xsl:template match="/Form">
<MaxPostInvoice>
<xsl:attribute name="xsi:noNamespaceSchemaLocation">C:\Program Files (x86)\MaxPostInvoice-v1.18.xsd</xsl:attribute>
<Header>
<VendorID>
<xsl:for-each select="Fields">
<xsl:for-each select="Supplier_ID">
<xsl:for-each select="#source">
<xsl:attribute name="source"><xsl:value-of select="."/></xsl:attribute>
</xsl:for-each>
</xsl:for-each>
</xsl:for-each>
<xsl:for-each select="Fields">
<xsl:for-each select="Supplier_ID">
<xsl:for-each select="#confidence">
<xsl:attribute name="confidence"><xsl:value-of select="."/></xsl:attribute>
</xsl:for-each>
</xsl:for-each>
</xsl:for-each>
<xsl:for-each select="Fields">
<xsl:for-each select="Supplier_ID">
<xsl:for-each select="#rawContents">
<xsl:attribute name="rawValue"><xsl:if test="//Fields/Supplier_ID[#rawContents = '']"><xsl:value-of select="''"/></xsl:if><xsl:if test="//Fields/Supplier_ID[#rawContents != 'X']"><xsl:value-of select="."/></xsl:if></xsl:attribute>
</xsl:for-each>
</xsl:for-each>
</xsl:for-each>
<xsl:for-each select="Fields">
<xsl:for-each select="Supplier_ID">
<xsl:for-each select="#contents">
<xsl:attribute name="value"><xsl:if test="//Fields/Supplier_ID[#contents = 'X']"><xsl:value-of select="''"/></xsl:if><xsl:if test="//Fields/Supplier_ID[#contents != 'X']"><xsl:value-of select="."/></xsl:if></xsl:attribute>
</xsl:for-each>
</xsl:for-each>
</xsl:for-each>
</VendorID>
<AllocationNumber>
<xsl:attribute name="rawValue">
<xsl:if test="number(./Fields/Supplier_ID/#contents) >= 985000 and number(./Fields/Supplier_ID/#contents) <= 989999">
<xsl:value-of select="FX"/>
</xsl:if>
</xsl:attribute>
<xsl:attribute name="value">
<xsl:if test="number(./Fields/Supplier_ID/#contents) >= 985000 and number(./Fields/Supplier_ID/#contents) <= 989999">
<xsl:value-of select="FX"/>
</xsl:if>
</xsl:attribute>
</AllocationNumber>
</Header>
</MaxPostInvoice>
</xsl:template>
</xsl:stylesheet>
This is the input XML:
<Form name="FP0001">
<Fields>
<Supplier_ID contents="985000" rawContents="" source="OCR" confidence="100"/>
<Supplier_Name contents="Leifheitstr" rawContents="" source="OCR" confidence="100"/>
<Supplier_Street contents="abcde" rawContents="" source="OCR" confidence="100"/>
</Fields>
</Form>
Result
<Header>
<VendorID source="OCR" confidence="100" rawValue="" value="985000 " />
<AllocationNumber rawValue="" />
</Header>

Answer 1

You have not provided a input XML, if your XPath is correct, you could do:
<xsl:attribute name="rawValue">
<xsl:if test="number(./Fields/Supplier_ID/#contents) >= 985000 and number(./Fields/Supplier_ID/#contents) <= 989999">
<xsl:value-of select="FX"/>
</xsl:if>
</xsl:attribute>
<xsl:attribute name="rawValue">
<xsl:if test="number(./Fields/Supplier_ID/#contents) >= 985000 and number(./Fields/Supplier_ID/#contents) <= 989999">
<xsl:value-of select="FX"/>
</xsl:if>
</xsl:attribute>
If it not works share your input XML and more of your XSLT (complete).

Answer 2

Why do you have the same attribute twice? In any case, you need to change:
<xsl:value-of select="FX"/>
to:
<xsl:value-of select="'FX'"/>
BTW, it seems to me you could simplify this thing significantly to something like:
<xsl:template match="/Form/Fields">
<MaxPostInvoice xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="C:\Program Files (x86)\MaxPostInvoice-v1.18.xsd">
<Header>
<VendorID source="{Supplier_ID/#source}" confidence="{Supplier_ID/#confidence}" >
<xsl:attribute name="rawValue">
<xsl:if test="Supplier_ID/#rawContents != 'X'">
<xsl:value-of select="Supplier_ID/#rawContents"/>
</xsl:if>
</xsl:attribute>
<xsl:attribute name="value">
<xsl:if test="Supplier_ID/#contents != 'X'">
<xsl:value-of select="Supplier_ID/#contents"/>
</xsl:if>
</xsl:attribute>
</VendorID>
<AllocationNumber>
<xsl:attribute name="rawValue">
<xsl:if test="number(Supplier_ID/#contents) >= 985000 and number(Supplier_ID/#contents) <= 989999">
<xsl:value-of select="'FX'"/>
</xsl:if>
</xsl:attribute>
</AllocationNumber>
</Header>
</MaxPostInvoice>
</xsl:template>