You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Dennis Davis. Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, please be on hold.

USER: Sure.

ASSISTANT: Thank you for your time, we do not found any active reservation in your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.