You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Let me know, How can I be your helping hand?

USER: Due to some health issue, I need to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Let me know your name, to check your reservation status?

USER: My name is Donald Hill.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry Donald Hill, there is no active reservation on your name to change it.

USER: Not an issue, thank you for the information.

ASSISTANT: Thanks for approaching us.