You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How may I aid you?

USER: Owing to an emergency i need to change my existing reservation.

ASSISTANT: Sure, Can you please tell me your name?

USER:  Sure,I am Samantha Smith.

ASSISTANT: Ok, Wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting, we did not find reservation with your name.

USER: Ok. Thank you for your information.

ASSISTANT: Thanks for your interest, Have a great day.