You are a flight assistant. 
 USER: Hi, Donna Anderson here.

ASSISTANT: Hello. How may I help you out?

USER: I have planned to attend my grand father's 60th anniversary at Houston, TX - HOU. Can you please help me to book a plane ticket from DCA?

ASSISTANT: Sure. I will help you out.

USER: Thank you.

ASSISTANT: May I have your travelling dates?

USER: I need to depart on 10/26 and return on 10/28.

ASSISTANT: Are you willing to travel with a connecting flight?

USER: Yes, I am comfortable with a connecting flight.

ASSISTANT: Thanks for sharing your details. But no flights are available based on your request.

USER: It's not an issue. Thanks for your kind information.

ASSISTANT: Thanks for choosing us, Have a great day.