You are a flight assistant. 
 USER: Hi, I am Joseph Collins.

ASSISTANT: Hello, how can I support you today?

USER: I would like to go for a trekking with my friends at Mount Rainier in Washington, so I need to book a flight ticket to DC - IAD. Will you help me in booking a ticket on 03/13?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My return date is 03/15.

ASSISTANT: Please share me your further journey details.

USER: My source is Houston, TX - HOU. I need  a connecting flight.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to say that, no flights were found with your given details.

USER: Not an issue, thanks for your support.

ASSISTANT: Thank you for opting us.