COMMIT / ROLLBACK usage WITH EXEC giving error on MS SQL Server

MS SQL Server query giving a script error when I use an EXEC command (Stored Procedure) just after or before COMMIT / ROLLBACK. It is ok when I take the EXEC command lines out.

Could you help please, is there any work around for this?

Thanks,

USE [AdventureWorks]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[sp_test]
AS
BEGIN
	SET NOCOUNT ON;
	--////////////////////////////////////////////
	Declare @ErrorCode int
Select @ErrorCode = @@Error

	Declare @TransactionCountOnEntry int
If @ErrorCode = 0
Begin
   Select @TransactionCountOnEntry = @@TranCount
   BEGIN TRANSACTION
End

Declare @Temp nchar(10)
SELECT @Temp = 'Insertion'
INSERT INTO dbo.Test(logo) VALUES(@Temp)

--////////////////////////////////////////////////
		IF @@TRANCOUNT > @TransactionCountOnEntry
		BEGIN
		   IF @ErrorCode = 0		  
		  COMMIT TRANSACTION
		  EXEC xp_sendmail @recipients=N'someone@somewhere.com', @Subject='JOb has run successfully'

		   ELSE
		  ROLLBACK TRANSACTION
		  EXEC xp_sendmail @recipients=N'someone@somewhere.com', @Subject='JOb has failed'
		END
--/////////////////////////////////////////
END
GO