You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Ryan Gonzalez here.

ASSISTANT: Nice to meet you Ryan.

USER: I want to change my reservation. Can you please help me for changing my reservation?

ASSISTANT: Sure, I will help you.

USER: Ok.

ASSISTANT: Please wait a moment to check your previous reservation.

USER: Sure, I will wait.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: Thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.