You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, may I know your name to check the reservation list?

USER: My name is Timothy Hernandez.

ASSISTANT: Sorry, no reservation found under your name to make changes further.

USER: Ok, not an issue. Thank you for your help.

ASSISTANT: Thank you for reaching us.