sql if conditons

[rvvvprasad]

can any one explain what below code means

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_ht_litigation_ht_mast]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1)
ALTER TABLE [dbo].[ht_litigation] DROP CONSTRAINT FK_ht_litigation_ht_mast
GO

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_ht_mutation_Ht_mast]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1)
ALTER TABLE [dbo].[ht_mutation] DROP CONSTRAINT FK_ht_mutation_Ht_mast
GO

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_Ht_tran_Ht_mast]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1)
ALTER TABLE [dbo].[Ht_tran] DROP CONSTRAINT FK_Ht_tran_Ht_mast
GO

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

[Rabbit]

If there is a foreign key constraint on those first 3 tables, it drops the constraint. If the last table is a user table, it drops the table.