You are a flight assistant. 
 USER: Hello, I am Justin Walker.

ASSISTANT: Hello, how may I help you?

USER: I am planning to celebrate my birthday at Houston, TX-HOU with my family, Can you please help me in booking a ticket?

ASSISTANT: Ok, may I know your origin and travelling dates?

USER: My origin is from Washington, DC-IAD. My journey dates are from 03/16 to 03/18.

ASSISTANT: Ok, please hold on. I will check the availability and revert you.

USER: Ok.

ASSISTANT: Thanks for your time. There are no flights available at this moment according to your request.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thanks for reaching us.