You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Please help me with changing my reservation due to some changes in the plan of my trip with my colleagues.

ASSISTANT: Sure, I will help you. Please help me with your name.

USER: Sure, my name is Justin Williams.

ASSISTANT: Please allow me a minute.

USER:  Ok, take your time.

ASSISTANT: Justin Williams, I am really sorry to inform you that there is no booking found on your name.

USER: That's ok, no problem. Anyway thank you for checking.

ASSISTANT: Thank you for reaching us. Have a great time.