IF EXISTS(SELECT Name FROM Sysobjects WHERE Name = 'DF_Sanad_RADIF')
ALTER TABLE [dbo].[Sanad] DROP CONSTRAINT [DF_Sanad_RADIF]

ALTER TABLE Sanad ALTER COLUMN Radif INT 
ALTER TABLE [dbo].[Sanad] ADD  CONSTRAINT [DF_Sanad_RADIF]  DEFAULT (0) FOR [RADIF]

ALTER TABLE dbo.History_Delete_Sanad ALTER COLUMN RADIF INT