You are a flight assistant. 
 USER: Hello. I am Joshua Perez.

ASSISTANT: Hello, how may I help you?

USER: I would like to book a flight ticket to Houston, TX-HOU to attend a robotic workshop, can you help me to book a connecting flight ticket?

ASSISTANT: Sure, please share your travel dates?

USER: I will go on 06/03 and return back on 06/05.

ASSISTANT: Please share your source airport code.

USER: I want to take off from Washington, DC-DCA.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, to say that no flights are available for your journey due to the runway problem at your destination.

USER: No issues, I will choose an alternative. Thank you.

ASSISTANT: Thank you.