You are a flight assistant. 
 USER: Hi. I am Donna Adams.

ASSISTANT: Hello. How can I help you out today?

USER: I want to book a ticket.

ASSISTANT: Could you please  let me know your source and destination ?

USER: My departure is from Los Angeles, CA - LAX to Dallas & Fort Worth, TX - DFW. My travelling dates are from May 21 to May 23. Price limit is 200 with one connection.

ASSISTANT: Please wait a while I will get you back.

USER: Sure.

ASSISTANT: Thanks  for being patient . unfortunately, There are no flights found.

USER: Thanks for your information.

ASSISTANT: Thank you for contacting us.