You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Lisa Brown.

ASSISTANT: How can I amend you?

USER: I would like to change my recent existing reservation because my friend who is participating in gun shooting has been postponed. Can you help me?

ASSISTANT: Sure. Wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, There is no reservation found with your name.

USER: No issue, thank you.

ASSISTANT: Thanks for opting us.