Script and XSL codes

Hi all,
First, I am sorry if I post this message in the wrong
list.
Second, I have the following codes, it keeps giving me
the error: 'document.CaseManager.PrsnID.value' is null
or not an object.  PLease help!
Javascript:
-----------

<script language='javascript'>
        function casemanager()
                {
                        var casemanager =  "../scripts/CaseManager.asp" +
"?PrsnID=" + document.CaseManager.PrsnID.value +
"&amp;SysID=" + document.CaseManager.SysID.value                
//alert(helppage)
                        var props =
"dependent=yes,resizable=yes,height=400,width=350,status=no,toolbar=no,menubar=no,scrollbars=yes,top=10,left=300"
                        helpwin =
window.open(casemanager,'CaseManager',props );
//,location=no
                        helpwin.focus()
        }
</script>

xsl code:
---------

<xsl:template match="Service">
        <tr class="Grid">
                <xsl:attribute name="style">background-color:
<xsl:eval>fnIsOdd()</xsl:eval></xsl:attribute>
                <TD ALIGN="CENTER" nowrap=""
headers="Program"><xsl:value-of select="Program"
/></TD>
                <TD ALIGN="CENTER" nowrap=""
headers="Begin"><xsl:value-of select="Begin" /></TD>
                <TD ALIGN="CENTER" nowrap=""
headers="End"><xsl:value-of select="Servd_Thru"
/></TD>
                <TD ALIGN="CENTER" nowrap=""
headers="SiteName"><xsl:value-of select="Site_Name"
/></TD>
                <TD ALIGN="CENTER" nowrap=""
headers="County"><xsl:value-of select="Site_County"
/></TD>
                <TD ALIGN="CENTER" nowrap=""
headers="Phone"><xsl:value-of select="Site_Phone"
/></TD>
                <TD ALIGN="CENTER" nowrap="" headers="CaseManager">
                        <form name="CaseManager" action="" method="post">
                                <input type="hidden" name="PrsnID">
                                        <xsl:attribute 
name="value"><xsl:value-of
select="//Client/PrsnID" /></xsl:attribute>
                                </input>
                                <input type="hidden" name="SysID">
                                        <xsl:attribute 
name="value"><xsl:value-of
select="//Client/SysID" /></xsl:attribute>
                                </input>
                                <input type="button" value="Case Manager" 
onClick="casemanager();"></input>
                        </form>
                </TD>
        </tr>
</xsl:template>

=====
"It is essential to know that to be a happy person, a happy family, a happy 
society, it is very crucial to have a good heart, that is very crucial,"
Dalai Lama

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list