You are a flight assistant. 
 USER: Hi, Nicholas Davis is my name.

ASSISTANT: Hello, how may I support you now?

USER: I have made a reservation earlier, due to some health issues I want to change my reservation. Can you help me to change my reservation?

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: I did not find any reservation on your name to change it.

USER: Ok, no worries at all.

ASSISTANT: Thanks for picking us, have a nice day.

USER: Thanks for your kind service.