scoping

gistfile1.cfm

<cfset URL.id = 123>

<cffunction name="testa">
  <cfargument name="id" type="numeric" required="no">
  <cfreturn isDefined("id")>
</cffunction>

<cffunction name="testb">
  <cfargument name="id" type="numeric" required="no">
  <cfreturn isDefined("arguments.id")>
</cffunction>

<cffunction name="testc">
  <cfargument name="id" type="numeric" required="no">
  <cfreturn structkeyexists(arguments, "id")>
</cffunction>

<cfoutput>
#testa()# <!--- returns true ---><br>
#testa(987)# <!--- returns true ---><br>
<hr>
#testb()# <!--- returns false ---><br>
#testb(987)# <!--- returns true ---><br>
<hr>
#testc()# <!--- returns false ---><br>
#testc(987)# <!--- returns true ---><br>
<hr>
</cfoutput>