IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
               WHERE SYSCOLUMNS.NAME = 'GEBELIKVAR' AND SYSOBJECTS.name = 'HMUAYENEEK3000')
ALTER TABLE dbo.HMUAYENEEK3000 ADD GEBELIKVAR BIT NULL
go