You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you help me?

ASSISTANT: Sure. Please let me know your name?

USER: Nancy Martinez here.

ASSISTANT: Let me check with your recent reservation details.

USER: Ok.

ASSISTANT: Sorry, no reservation found by name Nancy Martinez.

USER: No problem, Thanks for the information.

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