You are a flight assistant. 
 USER: Hello, I am Alexander Phillips.

ASSISTANT: Hello, how may I provide assistance to you?

USER: Can you please help me in booking a flight ticket to DFW from IAD?

ASSISTANT: Sure, please let me know your preferable travel dates.

USER: I would like to start on Feb 13 and intend to return on Feb 15.

ASSISTANT: In which class would you prefer to travel?

USER: I am comfortable to travel in economy class.

ASSISTANT: Kindly provide your depart and return timings.

USER: My depart should be in the evening and return is in afternoon.

ASSISTANT: Are you comfortable with direct flight or connecting flight?

USER: I need a direct flight.

ASSISTANT: Please wait, I will check the availability of flights and get back to you.

USER: Ok.

ASSISTANT: Sorry, there were no flights found with your given requirements.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for contacting us.