BUG #3941: Insert Error

The following bug has been logged online:

Bug reference:      3941
Logged by:          gnp yadav
Email address:      gnperumal@gmail.com
PostgreSQL version: 8.1
Operating system:   Ubuntu Linux
Description:        Insert Error
Details:

CREATE TABLE sentence
(
  sentence_id serial NOT NULL,
  citation_id int8 NOT NULL,
  sen_offset int8 NOT NULL,
  sen_length int8 NOT NULL,
  sen_type varchar(10)[] NOT NULL,
  CONSTRAINT sentence_id PRIMARY KEY (sentence_id),
  CONSTRAINT citation_id FOREIGN KEY (sentence_id)
      REFERENCES citation (citation_id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION
) ;

INSERT INTO sentence (sentence_id, citation_id, sen_offset, sen_length,
sen_type) VALUES (NULL,1,2,3,asd");


As i Got This type error frequently

ERROR:  column "asd" does not exist

please guide me, Advance thanks to for my teacher.