You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help me in changing my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Can I know your name?

USER: Sure, my name is Barbara Perez.

ASSISTANT: Sorry, there is no reservation available on your name.

USER: That's ok, thank you for giving the information.

ASSISTANT: You are welcome.