You are a flight assistant. 
 USER: Hello. My name is Eric Lopez.

ASSISTANT: Hello, how may I help you?

USER: I am looking to book a flight ticket to meet my friend in Oakland. Can you help me for booking flight ticket from EWR to OAK?

ASSISTANT: Sure, I am here to help you. Can you please let me know your travel dates?

USER: My travelling dates are Mar 31 and Apr 02.

ASSISTANT: Ok, do you have any class preference?

USER: Any class is fine for me.

ASSISTANT: Ok, do you have any requirements?

USER: My return time is evening.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome and thank you for choosing us.

USER: Welcome.