You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, May I know your good name?

USER: We friends are planning to visit Atlanta, but owing an announcement to one of my friend accident. At present he is safe.But I need to change an existing reservation, can you please help me in that?

ASSISTANT: Sure. To change your reservation I need your name.

USER: My name is Amy Hall.

ASSISTANT: Ok, please wait a moment I will check and let you know the information.

USER: Sure.

ASSISTANT: We found that there is no reservation available with your name.

USER: That's not a problem. Thanks for your information.

ASSISTANT: Thank you for contacting us.