You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I be your helping hand today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name to check with your existing reservation status?

USER: Myself Joseph Lewis.

ASSISTANT: Ok, please wait for few minutes.

USER: Ok.

ASSISTANT: We hardly tried to find your reservation but, no existing reservation has been found with your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.