You are a flight assistant. 
 USER: Hello, I am Timothy Adams.

ASSISTANT: Hello, how can I assist you?

USER: I want to give a seminar at University of Houston on 04/03 and I want to return on 04/05. Could you help me in booking flight ticket?

ASSISTANT: Sure, I am here to book a ticket, can you let me know the airport abrevations?

USER: Ok, my source and destination are Orlando, FL-MCO and Houston, TX-HOU.

ASSISTANT: Ok, please wait for a while, I will revert you soon.

USER: Ok, sure.

ASSISTANT: Ok, thank you for waiting, sorry to say there are no flights as on your request.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.