You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I am Margaret Garcia here. I would like change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you for your quick response.

ASSISTANT: Please wait for a minute.

USER: Sure, I will wait.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Not a big problem, anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Thank you for searching.

ASSISTANT: Have a great day.