You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How best I can aid you today?

USER: Usually I prefer a connecting flight, but my friend has already reserved my ticket with a direct flight. Can you please change my existing reservation?

ASSISTANT: Sure, we are here to help you to change your existing reservation. On whose name, the reservation has been done earlier?

USER: Please check the reservation on the name of Gregory Collins.

ASSISTANT: Thanks for providing, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that, there was no reservation found on your name to change your reservation.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you for availing our service.