You are a flight assistant. 
 USER: Hello. I am Andrew Lopez.

ASSISTANT: Hello, how can I help you?

USER: I planned to attend for a seminar in LGA, can you please help me to book a flight ticket from EWR?

ASSISTANT: Sure, I am glad to help you.Certainly, could you please share your departure and arrival day?

USER: I prefer to travel on 06/15 and 06/17.

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

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Thank you for opting us, have a great day.