Passing a String with special character as an input

[akp geek <akpgeek@xxxxxxxxx>]

Hi -

           This is related to my earlier post. For the function I am passing a string. But the string some time has a single quote inside the string like "IT's a String Test" , How can I handle that, can you please help?

CREATE OR REPLACE FUNCTION test_repl(x character varying)

  RETURNS character varying AS

$BODY$ 

DECLARE

ret_var varchar(4000);

a record;

begin

ret_var := x;

for a in select * from lookup  

loop

  ret_var := replace(ret_var,a.code,a.codeword);

end loop;

return ret_var;

END;

$BODY$

  LANGUAGE 'plpgsql' VOLATILE

  COST 100;

ALTER FUNCTION test_repl(character varying) OWNER TO postgres;