You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brenda Campbell.

ASSISTANT: How can I assist you?

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

ASSISTANT: Sure, please give me a minute Brenda.

USER: Sure, take your own time.

ASSISTANT: Brenda, there is no reservation found with your details.

USER: Ok, not an issue. May be something went wrong while booking the ticket previously. Anyways, thank you for providing information.

ASSISTANT: Thank you for contacting us.