You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation, Can you help me out?

ASSISTANT: Sure, can I have your name please?

USER: Sure, My name is Nancy Thomas.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your given name.

USER:  Oh! May be I have done a wrong reservation, Anyways thank you for the information.

ASSISTANT: Thank you for opting us.