xsl: How to update varial value in a loop

[maxin]

I have a xml file:

<E1MBXYI SEGMENT="1">
...
<CHARG>1000024187</CHARG> 
...
</E1MBXYI>
<E1MBXYI SEGMENT="1">
...
<CHARG>1000024187</CHARG> 
...
</E1MBXYI>
<E1MBXYI SEGMENT="1">
...
<CHARG>1000024188</CHARG> 
...
</E1MBXYI>

I want to transform it to another xml file, where I should only take the item CHARG if it has a differetn value.
I wrote the following code:

<DataArea>
        <xsl:variable name="V_MaterialLot" select="''"/>
        <xsl:for-each select="E1MBXYI">
                <xsl:if test="$V_MaterialLot != CHARG">
                        <MaterialInformation>
                                <ID>
                                        <xsl:value-of select="CHARG"/>
                                        <xsl:variable name="V_MaterialLot" select="CHARG"/>
                                <ID>
                        <MaterialInformation>
                </xsl:if>
        </xsl:for-each>
</DataArea>

However, I can not define the varial V_MaterialLot twice in the same xsl.
Does someone have a solution to me?
Regards
maxin

[Dormilich]

if you want to use only the unique <CHARG>s, then you can try Muenchian Grouping before doing the output.

[jkmyoung]

More specifically it would be like:

<xsl:for-each select="E1MBXYI[not (CHARG = preceding-sibling::E1MBXYI/CHARG)]">

No variables needed.

[maxin]

Thanks all for the solution.
I will try it.

Regards maxin