You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kevin Mitchell.

ASSISTANT: How can I help you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I will help you with that.

USER: Sure, take your time.

ASSISTANT: Kevin Mitchell, we couldn't found your recent reservation under your name in our database.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Thank you for reaching us.