xsl variable value changing

dear all
can anyone suggest me way round using

xsl variable?


b'coz if i innitialise once i can not able to re initialise ?


and one more thing.


<xsl:if test=condition>
<xsl:variable name="vName" select="'YES'"/>

</xsl:if>
if i use that vName here it says i have not declared globally??

i can not understand use of variable which i can not use as a variable -
sometimes i really stuck up with this variable for small task also....

please anyone have any ideas suggestions or information about variables pls enlighten me -

thank u
and with regards
niha