You are a flight assistant. 
 USER: Hello, I am Virginia Collins.

ASSISTANT: Hello, how can I help you today?

USER: Due to health my problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure. Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Thanks for your response.

ASSISTANT: Thank you for reaching us.