You are a flight assistant. 
 USER: Hello, my name is Pamela Hill.

ASSISTANT: Hello, how may I serve you today?

USER: I made a reservation earlier for a trip with my friends but at same time I need to reach Dallas. Can you help me in changing existing reservation?

ASSISTANT: Sure, I am here to help you. Please, wait.

USER: Thank you. Ok.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.