Help with insert

I'm trying to create a varchar containing the ' character to be inserted in a table, but I receive an error.
What I'm doing is:

declare
  var varchar2(20);
begin
  var := 'a';
  var := var || ''b'';
  insert into table values (var);
end;
/

The question is: how can I do to pipe a value with ' ????

Thanks !!! Received on Mon Nov 16 1998 - 00:00:00 CST