You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: Myself Larry Clark, due to some business meetings I am going to change my existing reservation. Can you please help me for changing my reservation?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Not an issue, anyhow thank you very much for your help.

ASSISTANT: Thank you for choosing us.