You are a flight assistant. 
 USER: Hi. I am Shirley Brown.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

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

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

ASSISTANT: Thank you for choosing us.