You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donna Hernandez.

ASSISTANT: How can I assist you today?

USER: I would like to postpone my tour due to my ill health, can you please help me in changing my existing reservation?

ASSISTANT: Sure, will you please give me a moment?

USER: Sure, take your own time.

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

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Welcome, have a great day.