You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carolyn Garcia.

ASSISTANT: How can I assist you today.

USER: My meeting at Dallas got postponed, can you please help me by changing my existing reservation?

ASSISTANT: Sure, I will help you with this. Please wait for a moment.

USER: Thank you.

ASSISTANT: Sorry Garcia, no reservation is found.

USER: Ok, not an issue. May be something went wrong while booking the ticket.

ASSISTANT: Thank you for reaching us.

USER: Thank you for providing information.