How to pass the right value by "xsl:value select=" to URL in the generated HTML page

Hi all friends,
    We are using our XSL to generate a HTML page. In the generated page, we
have an URL to call us back.  In the URL, we need to pass some parameters
with France characters. These France characters are displayed correctly in
the page. However, the value of these characters passed into URL are not
right.

    Our XSL is something like:

<?xml version="1.0" encoding="ISO-8859-1" ?>
..........
this month: <xsl:value-of select="$em"/>

<xsl:element name="img">
    <xsl:attribute name="src" >
        .........?page=xmlstmt&amp;clientLanguage=F&amp;Legend=<xsl:value-of
select="$em"/>&amp;chartinfo.........."
    </xsl:attribute>       
</xsl:element>
..........

    As mentioned above, the right value of "$em" (déc) is displayed for
"this month".  However, the wrong value of "$em" (déc) is passed into img's
src.
    We also noticed that the following line is always automatically added
into the generated HTML:
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
    We tried many ways, with no success, to overweight it as:
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    All your suggestions and advices are appreciated.

Gordon