You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a direct flight to meet my sister and enjoy my holiday trip, can you help me with booking?

ASSISTANT: Sure, let me know your travel dates please?

USER: My travel dates are May 27 and May 29.

ASSISTANT: Could you please share me your airport codes?

USER: My airport codes are DFW to MSP.

ASSISTANT: Do you need any preference?

USER: No.

ASSISTANT: Can I know your name please?

USER: I am Shirley Lee.

ASSISTANT: Sorry to inform you that there are no flight services available on your given dates.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for contacting us.