DECLARE @Id Int                               
SELECT @Id = Id From sysobjects Where Name = 'Tbl_ScoreClub'
IF not Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'CreatedOn')
  ALTER TABLE Tbl_ScoreClub
        ADD CreatedOn DATETIME NULL   
IF not Exists(SELECT * FROM syscolumns WHERE id = @Id and Name = 'CreatedBy')
  ALTER TABLE Tbl_ScoreClub ADD CreatedBy SMALLINT NULL;