You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Charles Wilson.

ASSISTANT: Yes Charles.

USER: I need to modify my dates in my recent reservation, can you help me out please?

ASSISTANT: Sure, I am glad to help you in that, please hold on for a moment to check your reservation status.

USER: Sure, take your own time.

ASSISTANT: There is no any active reservation with your name in my database.

USER: That's ok, no problem. Thank you for your help.

ASSISTANT: It's my pleasure.