You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please change my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Sure, we are happy to help you. Please let me know your good name to proceed further.

USER: Sure, my name is Jack Walker.

ASSISTANT: Sorry, we did not find any active reservation on your name in our data.

USER: That's fine, thank you for giving the information anyways.

ASSISTANT: Thank you for contacting us.