You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I best support you now?

USER: Can you please help me in changing my reservation due to some health issues?

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Sure, myself Frank Davis.

ASSISTANT: Ok, Please allow me a moment to check for the previous reservation in our database.

USER: Sure, I will wait for your response.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

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

ASSISTANT: Thanks for reaching us, wish you a great day.