You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am planning to change an exiting reservation, due to health issue.Can you please change my reservation?

ASSISTANT: Sure. May I know your name?

USER: My name is Patricia Brown.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting, We didn't found any reservation by this name.

USER: That's fine, thank you for your help.

ASSISTANT: Thank you for opting us.