You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Can you please change my existing reservation?

ASSISTANT: Sure, We are here to help you. May I know your name?

USER: Sure, I am Amy Collins.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: We didn't found any reservation by this name.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you for reaching us.