You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Helen King.

ASSISTANT: How may I assist you?

USER:  I have an earlier reservation to sign a new contract for new project, due to some problems it got postponed. Can you please change my existing reservation?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Wait a moment please.

USER: Sure, I will wait for your response.

ASSISTANT: Helen King, we haven't found any reservation under your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.