You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Stephanie Carter.

ASSISTANT: How can I provide service to you?

USER: Could you please help me in changing my existing reservation?

ASSISTANT: Sure, please hold on.

USER: Ok.

ASSISTANT: Thanks for holding on, we do not found any active reservation in your name.

USER: Not a problem, thank you.

ASSISTANT: Thanks for contacting us.