You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I best help you today?

USER: I am Brenda Allen. I want to change my existing reservation, due to health issue. Can you help me in my changing reservation?

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

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

USER: Not an issue. Thank you for your kind information.

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