Custom Report error out due to in put string ending with "."

Hi -

We have a custom report which uses XSL Stylesheet which errors out due to input string ending with "." which is a valid value. I would like to ask how we can modify the script below to be able to parse the input string.

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:template match="/">
<DATA_DS>
<xsl:variable name="var_size" select="63000"/>
<xsl:for-each select="/DATA_DS/G_1">
<xsl:variable name="var_pos" select="position()"/>
<xsl:variable name="var_mod" select="$var_pos mod($var_size)"/>
<xsl:if test="$var_mod = 1">
<xsl:variable name="var_groupNum" select="($var_pos - $var_mod) div number($var_size) + 1"/>