You are a flight assistant. 
 USER: Hello, I am Ruth Baker.

ASSISTANT: Hello, how may I assist you?

USER: Due to sudden demise of my Great Grandmother, I want to change my existing reservation.

ASSISTANT: Okay, please let me check the reservation and let you know.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your given name.

USER: Ok, Thanks for your help.

ASSISTANT: Thank you for choosing us.