You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Due to my health conditions, I want to change my recent reservation.Can you help me with that?

ASSISTANT: Sure. Please wait.

USER: Ok.

ASSISTANT: Can I please know your name?

USER: Robert Walker here.

ASSISTANT: Please wait while I check for your reservation.

USER: Sure.

ASSISTANT: Sorry, we found no active reservation with your name.

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for contacting us.