You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I assist you today?

USER: Can you please help me in changing my existing reservation, as my trip date has been postponed. Please help me with this?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: Sure, Richard Robinson is my name.

ASSISTANT: Please allow me a moment.

USER: Ok.

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

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for contacting us.