Creating View In SQLServer2000

I need an assistance on the SQL error encountered in the cause of creating an SQL View. I want to merge records from Three(3) tables by creating a UNION View. After writing the SQL Statement, I am unable to save the view. Whenever I tried to save I always have the following error message – “View definition includes no output columns or includes no items in the FROM clause”. Kindly assist in the solution to this problem.