You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I guide you today?

USER: I am Ronald Phillips. I just want to change my existing reservation, due to health issue. Can you help me out?

ASSISTANT: Sure, we are here to help you to change your reservation. Please wait for a while.

USER: Sure, take your time.

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

USER: Not an issue. Thank you for your quick response.

ASSISTANT: Thank you for opting us.