Error Handling in SQL Server

BEGIN TRY

      select 1/0

END TRY

BEGIN CATCH

    DECLARE @ErrorMessage NVARCHAR(4000);

    DECLARE @ErrorSeverity INT;

    DECLARE @ErrorState INT;

    SELECT

        @ErrorMessage = ERROR_MESSAGE(),

        @ErrorSeverity = ERROR_SEVERITY(),

        @ErrorState = ERROR_STATE();

    RAISERROR (@ErrorMessage, -- Message text.

               @ErrorSeverity, -- Severity.

               @ErrorState -- State.

               );

END CATCH;