You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, I am here to help you. Can I know your name to check your details?

USER: My name is Jessica Brown.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: That's ok, not an issue. Thanks for your response.

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