IF EXISTS (SELECT 1 FROM syscolumns WHERE name = 'SCF40' AND ID = OBJECT_ID('SCF1') AND xtype <> 61)
BEGIN
  ALTER TABLE SCF1 DROP COLUMN SCF40

END
GO

IF EXISTS (SELECT 1 FROM syscolumns WHERE name = 'SCF41' AND ID = OBJECT_ID('SCF1') AND xtype <> 61)
BEGIN
  ALTER TABLE SCF1 DROP COLUMN SCF41

END
GO

IF NOT EXISTS (SELECT 1 FROM syscolumns WHERE name = 'SCF40' AND ID = OBJECT_ID('SCF1'))
  ALTER TABLE SCF1 ADD SCF40 datetime 
GO

IF NOT EXISTS (SELECT 1 FROM syscolumns WHERE name = 'SCF41' AND ID = OBJECT_ID('SCF1'))
  ALTER TABLE SCF1 ADD SCF41 datetime 
GO