look up in form

1) create a simple form  with a simple data source
2) we can add a simple table in data source and drag both in design and
3)under design we can go to particular field  and  over ride method  called look up

4) before  the super declare all the query, systablelook up, querybuild data source

 then save the form and open the  form under the field  where we have over ridden the look up there a look up will be appeared and   rtequired  fields and look up will be created '