IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
               WHERE SYSCOLUMNS.NAME = 'GONDERIMTESLIMALAN' AND SYSOBJECTS.name = 'KANURUNU')
ALTER TABLE KANURUNU
   ADD GONDERIMTESLIMALAN nvarchar(50) NULL
GO