if exists (select * from dbo.sysobjects where Name = 'DF_TblEkhtetam_Tarikh')
ALTER TABLE [dbo].[TblEkhtetam] DROP CONSTRAINT DF_TblEkhtetam_Tarikh

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[TblEkhtetam]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[TblEkhtetam]