You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: As my scheduled got postponed for 1 week. But I have reserved my flight ticket long ago. Can you please help me to change my reservation which is under the name of Andrew Lewis?

ASSISTANT: Sure, please wait for some time.

USER: Ok, have your time.

ASSISTANT: There is no existing reservation found on your name.

USER: It's ok, it might not be booked successfully at the time of booking which I have done. Anyway thank you for the information.

ASSISTANT: Thank you for approaching us.