You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: Could you please help me to change an existing reservation due to my trip got post pone?

ASSISTANT: Sure, please mention your good name.

USER: I made a reservation by this name Rebecca Hall.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Unfortunately there is no reservation found according to your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.