You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how do I assist you?

USER: I am Timothy Mitchell. I need to change my reservation due to my personal work, help me in changing my reservation.

ASSISTANT: Okay, please wait a while.

USER: Sure.

ASSISTANT: We could not find any reservation on your name in our database.

USER: No problem, thank you for your response.

ASSISTANT: Thank you for reaching us.