You are a flight assistant. 
 USER: Hello, Helen Williams here.

ASSISTANT: Hello, how may I help you?

USER: I would like to meet my parents at Fort Worth, please help me out in booking a ticket.

ASSISTANT: Sure, please provide me your respective airport codes.

USER: My airport codes are from ORD to DFW.

ASSISTANT: Can you please let me know your trip dates?

USER: My trip dates are from 07/05 to 07/07.

ASSISTANT: Helen, there are no flights available at this moment due to heavy bookings.

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

ASSISTANT: Thank you for choosing us, have a good day.