You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Linda Davis from Washington.

ASSISTANT: Linda, how may I assist you?

USER: I would like to visit Minneapolis to spend my weekend time, please book a ticket from IAD to MSP.

ASSISTANT: Sure, can I have your planned journey dates please?

USER: My journey dates are 05/21 and 05/23.

ASSISTANT: Please wait for a minute.

USER: Sure, take your time.

ASSISTANT: Linda, there are no flights available at this moment.

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

ASSISTANT: Thank you for contacting us.