IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
              WHERE SYSCOLUMNS.NAME = 'PGELDI' AND SYSOBJECTS.name = 'PEGITIMD')
ALTER TABLE dbo.[PEGITIMD] ADD PGELDI  bit NOT NULL CONSTRAINT [DF_PEGITIMD_IMZALANDIMI] DEFAULT (0)
GO