Hi thanks for the replies I used structKeyExists as per lyndon's recommendation, but the page throws an error if there is page.cfm without any sectorid parameter
<cfinclude template = "header.cfm">
<cfquery name="qNames" datasource="sales">
select * from COMPANY, sector
where COMPANY.sectorid = sector.sectorid
<cfif structKeyExists(url,"sectorID")>
and sector.sectorid = #url.sectorid#
</cfif>
</cfquery>
<cfquery name="sNames" datasource="sales">
select * from COMPANY, sector
where <cFIF IsDefined('url.sectorID')>
sector.sectorid = #url.sectorid#
</cfif>
</cfquery>
<CFQUERY name="sector" datasource="sales">
SELECT sectorId, sector
FROM sector
ORDER BY sector
</CFQUERY>
