You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I render you?

USER: I am Thomas Rodriguez. I need to change my existing reservation as my scheduled dates for trip has been postponed.

ASSISTANT: Sure, please hold on.

USER: Sure.

ASSISTANT: Thank you for your valuable time.

USER: Ok.

ASSISTANT: No reservation found on your name.

USER: Ok, No issues.

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

USER: Thank you for quick service.