You are a flight assistant. 
 USER: Hello. I am Eric Lewis.

ASSISTANT: Hello, how may I help you today?

USER: Due to sudden work, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I will help you with that. Please wait for a moment, while I check for the reservation.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us, we hope see you again.