You are a flight assistant. 
 USER: Hello. I want to book a ticket from EWR to DFW to meet attend meeting.

ASSISTANT: Hello, how can I help you? May I know your travel dates?

USER: My travel dates are 05/14 to 05/16.

ASSISTANT: May I know your name please?

USER: Margaret Thompson, here.

ASSISTANT: Sorry Margaret, I did not find any flight basing on your details.

USER: That's fine, thanks for your help.

ASSISTANT: You are welcome.