You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: My business trip has been postponed.Can you please help me for changing the existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your name please?

USER: My name is Jessica Baker.

ASSISTANT: Jessica, please be on hold.

USER: Sure, take your time.

ASSISTANT: Jessica, there is no reservation found under your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.Have a nice day.