XSL choose when $variable = $variable - xslt

Question

I'm trying to check if two XSL variables are the same:
<?xml version="1.0" encoding="UTF-8"?>
<files>
<file filename="export.csv" path="/export" active="true" ftp="false">
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:php="http://php.net/xsl">
<xsl:output method="text" encoding="UTF-8"/>
<xsl:variable name="quote">"</xsl:variable>
<xsl:variable name="sepstart" select="','"/>
<xsl:template match="/">
<xsl:text>"CustomerID"</xsl:text>
<xsl:variable name="second_check">0</xsl:variable>
<xsl:for-each select="orders/order">
<xsl:for-each select="items/item">
<xsl:variable name="output">
<xsl:variable name="first_check"><xsl:value-of select="normalize-space(../../increment_id)"/></xsl:variable>
<xsl:choose>
<xsl:when test="$first_check = $second_check">
Do something...
</xsl:when>
<xsl:otherwise>
Do something...
<xsl:variable name="second_check"><xsl:value-of select="normalize-space(../../increment_id)"/></xsl:variable>
</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:value-of select="$output" />
<xsl:text>
</xsl:text>
</xsl:for-each>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
</file>
</files>
However, it's just skipping over both and not outputting anything.
Can anyone point out what I'm doing wrong?

Answer 1

You cannot "re-declare" variables in XSL. When you write
<xsl:variable name="second_check">
<xsl:value-of select="normalize-space(../../increment_id)"/>
</xsl:variable>
That has no affect, because of this
<xsl:variable name="second_check">0</xsl:variable>
I can't help you though (yet), because I'm not really sure what you're trying to do