You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Ruth Lopez want to book a ticket to NY-EWR from NV-LAS, can you please help me in booking?

ASSISTANT: Sure, can you please share your travel dates?

USER: My travel dates are from Feb 10 to Feb 12.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Ruth Lopez, there is no flight available at your requested dates.

USER: Ok, no problem. Thank you.

ASSISTANT: You are welcome. Thank you for contacting us.