You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Stephen Turner.

ASSISTANT: How can I provide service to you?

USER: Can you change my reservation, which is done earlier?

ASSISTANT: Sure, please hold on for a second.

USER: Sure.

ASSISTANT: Thanks for being on hold, we do not found any reservation with your name.

USER: No worries, thank you for your information.

ASSISTANT: Thanks for approaching us, hope to serve you again.