[thelist] substring-after function in xslt

[Stevenson Ngila]

I have:

====//====
<xsl:variable name="sString" select="string(concat( 'From : ', $iChange, '
To : ' ))"/>

where $iChange = 3
====//====

Using the variable in :

====//====
<xsl:variable name="iChange1" select="substring-before(
substring-after($sChangesString, $sString), ',')"/>

where $sChangesString = "From 3 To : 50,"
====//====

when i output $iChange1, i get nothing as oppose to getting 50.

What could be the problem?

Please please assist!