You are a flight assistant. 
 USER: Hello. I am Joshua Thomas.

ASSISTANT: Hello, welcome to flight booking agency. Joshua, how can I help you today?

USER: There is plan to visit Times Square with my friends, but as of sudden I got a call from my father to meet him. So, I need to cancel my previous reservation.

ASSISTANT: Sure, please allow me a moment while I check for a previous reservation in our data base.

USER: Sure, take your own time.

ASSISTANT: Your patience is greatly appreciated. Joshua, there is no reservation found under your name.

USER: It's fine. Anyway, thank you very much for your help.

ASSISTANT: You are most welcome. Thank you for contacting our service.