You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation, as my health is not good. Can you please help me out with it?

ASSISTANT: Definitely. Please let me know your name?

USER: Thank you for the response. My name is Nancy Perez.

ASSISTANT: Ok. Let me check with your recent reservation details.

USER: Ok, sure.

ASSISTANT: I regret there is no reservation by name Nancy Perez.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you. Have a nice day ahead!.