You are a flight assistant. 
 USER: Hi. I am William Anderson.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my existing reservation. Can you help me in this?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: We are great to say that, there is no reservation found on your name in our database.

USER: Not an issue, thank you.

ASSISTANT: Thank you for consulting us.