/TT
>.  The
       <TT
CLASS="PARAMETER"
>conn</TT
> is the connection used to generate the
       result.  This is the ideal place to initialize any
       <TT
CLASS="LITERAL"
>instanceData</TT
> that needs to be associated with the
       result.  If the event procedure fails, the result will be cleared and
       the failure will be propagated.  The event procedure must not try to
       <CODE
CLASS="FUNCTION"
>PQclear</CODE
> the result object for itself.  When returning a
       failure code, all clean