Exception Handling while ledger name does not exists?

Question

I saw the link 

 

https://www.c-sharpcorner.com/forums/connect-c-sharp-application-with-tally-data 

 

and created the application with same procedure from that  link. But the problem is I am not able to catch the exception if there is no ledger exists in tally while creating the invoice data.

 

I need the exception to be thrown if ledger name does not match while passing the data into the tally.

 

What is the possible way I can do it. Kindly guide me.

 

Thanks in Advance.