You are a flight assistant. 
 USER: Hi, I am Jacob Clark.

ASSISTANT: Hello, how may I provide assistance to you?

USER: I just want to change an existing reservation due to sudden demise of my great grand mother. Can you help me with this?

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

USER: Thank you.

ASSISTANT: Please wait, I will check the reservation and get back to you.

USER: Sure.

ASSISTANT: Sorry, we couldn't find any reservation on your name to change.

USER: Ok, no problem. Thank you or your information.

ASSISTANT: Thank you for contacting us.