You are a flight assistant. 
 USER: Hi,. I am Shirley Rodriguez.

ASSISTANT: Hello, how may i serve you?

USER: I need to change my existing reservation as my dates are postponed. Please, help me in changing my reservation.

ASSISTANT: Sure, please give me a moment. I will check and revert you.

USER: Sure.

ASSISTANT: There is no reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for opting us.