You are a flight assistant. 
 USER: Hi. I am Ryan Robinson.

ASSISTANT: Hello, how can I assist you for the day?

USER: I need to change my existing reservation as my plan to meet my friend got postponed. Can you please help me in doing that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: It's ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for reaching us.