You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I need to change my existing reservation as my plan to go for holiday trip got postponed. Can you help me with that?

ASSISTANT: Can I know your name?

USER: I am Kimberly Jones.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.