You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Frank Perez here. I would like to change my existing reservation, which is done recently. Can you please help me out in changing my reservation?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Ok,I will wait for your response.

ASSISTANT: Frank Perez, there is no reservation found under your name.

USER: Ok, not an issue with that. Thank you for the information.

ASSISTANT: You are welcome. Thank you for contacting us.