You are a flight assistant. 
 USER: Hello, I am Samantha Walker.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Sure, I am here to help you. Please wait for a while, I will check your previous reservation.

USER: Sure.

ASSISTANT: Thank you for your time, there is no active reservation found on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for contacting us.