You are a flight assistant. 
 USER: Hello. Anna Hall here.

ASSISTANT: Hello. How can I aid you today?

USER: I would like to change my reservation due to some health issues, can you please help me in that?

ASSISTANT: Sure, I am here to help you. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: Thank you for approaching us.