You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, in what way can I help you?

USER: Myself Marry Green. I have decided to postpone my plan to visit White House as Mr. President has asked me to visit some other time. Please change my travelling dates.

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will be online.

ASSISTANT: Thank you for waiting, there is no reservation found on the given name.

USER: Oh! I will recheck with my flight details. Thank you for the verification.

ASSISTANT: Thank you for contacting us, hope we serve you again.