You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I need to change my reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: On which name can I change reservation?

USER: Please change with name Barbara Robinson.

ASSISTANT: I am sorry no reservation found on your name.

USER: It's ok fine, no problem. Thank you for your time.

ASSISTANT: Thank you for choosing us.