You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Rebecca Phillips. I want change my existing reservation, due to weather condition.

ASSISTANT: Sure, I will help you with the change of flight reservation.

USER: Thank you.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no reservation on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thanks for contacting us.

USER: Welcome.