You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I amend you?

USER: I want to change my existing reservation. Can you help me in this?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: We are here to help you. May I have your name?

USER: I am Samuel Thomas.

ASSISTANT: Ok. Please wait for some time, I will revert to you.

USER: Sure.

ASSISTANT: Thanks for your time, no reservation is found on your name.

USER: Not a problem ,thank you.

ASSISTANT: Thank you.