You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Christopher Roberts. I need a flight from LGA to PHL, can you help me out please?

ASSISTANT: Sure, help me with your trip dates.

USER: My trip dates are from 10/13 till 10/15.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: That's ok, no problem. Thank you for your help.

ASSISTANT: Thank you for opting us.