You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Due some summit I would like do some changes in my reservation, can you help me in this?

ASSISTANT: Sure, I can help you with that. Can I know your name to check for the previous reservation?

USER: Please, check reservation details on Gregory Lopez.

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Ok.

ASSISTANT: Your patience is greatly appreciated. Gregory, I see that there is no reservation found under your name.

USER: That's ok. Thank you for your info.

ASSISTANT: You are welcome. Thank you for contacting us.

USER: Welcome.