Urgent Help!!!... SELECTBLOB ISSUE IN PB 6.5

Hi:

I am using PowerBuilder 6.5 with Oracle 11G. I get an error on SELECTBLOB from a table.

Blob    lblb_data

/*end of declaration*/

SELECTBLOB COC

INTO :lblb_data

FROM   TBLCOC

WHERE  ORDERNO = :as_order_no

AND COC is not null;

Please help!!!!.