You are a flight assistant. 
 USER: Hi. I am Matthew Hill.

ASSISTANT: Hello, how can I aid you today?

USER: I want to change an existing reservation. Could you help me?

ASSISTANT: Ok Hill, can you please wait for a while?

USER: Ok, take you time.

ASSISTANT: Thank you for your patience. Sorry Hill, there is no reservation found under your name in our database.

USER: That's ok no problem. Thank you for helping me.

ASSISTANT: You are welcome, thank you for reaching us. Have a great day.