You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Can you help me to change my existing conversation?

ASSISTANT: Sure, for that please let me know your details?

USER: Sure, my name is Justin Williams.

ASSISTANT: Hold on for a moment. I will let you know as soon as possible.

USER: OK.

ASSISTANT: Unfortunately, no reservation is done on your name to change it.

USER: OK, thank you.

ASSISTANT: Thank you have a great day a head.