You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, welcome to airline agency.

USER: I am Nicholas Lewis.

ASSISTANT: How can I serve you?

USER: Due to some issue, I want to change my existing reservation. Please help me.

ASSISTANT: Ok. I will help you. Please wait a moment I will check the reservation with your name.

USER: Sure.

ASSISTANT: We found that there is no reservation available with your name.

USER: No issue. Thank you for quick response.

ASSISTANT: Thank you for reaching us.