Variable Scope

Hello,

So far I have not ran into any troubles with variable scope, and I am
refering to globabl variable scope - variables defined within my base
template.  I am having trouble now with a MAX_DATE variable I have
defined.  So, I am wondering about execution plan and where/when
variables are available.  Given the following inclusiong/import plan I
will attempt to describe where it appears that MAX_DATE(s) scope is
out-of-scope.

base_template.xsl
  MAX_DATE is defined (see definition below)

working_template_a.xsl
  {imports} base_template
  {includes} working_template_b.xsl
  {includes} working_template_c.xsl
  {includes} working_template_d.xsl
  {includes} ... additional working templates ..

MAX_DATE inside of any template definition inside of any included file
above is fine.  MAX_DATE used as part of a variable definition at the
top (outside a template rule) of any of these include files throws the
error:  "The variable or param MAX_DATE is either not defined or it is
out of scope".

Any ideas on this?


Note:  CreateNewDate template is defined in base_template.xsl
<xsl:variable name="MAX_DATE">
<xsl:call-template name="CreateNewDate">
  <xsl:with-param name="start_year" select="$FISCAL_YEAR" />
  <xsl:with-param name="start_month">06</xsl:with-param>
  <xsl:with-param name="start_day">30</xsl:with-param>
</xsl:call-template>
</xsl:variable>