Using Try Catch And Exception Handling in Procedures

CREATE PROCEDURE usp_InsertTest            
(                  
 @Name varchar(50),    
 @Add varchar(50),    
 @Sal int ,    
 @ErrMsg varchar(4000) output      
 )                  
AS      
declare @Err varchar(2000)
Begin
 begin try
  begin transaction    
  insert into Tbltest([Name],[Add],Sal) values(@Name,@Add,@Sal)      
  commit transaction  
 end try
 begin catch
  rollback transaction

 end catch  
End