You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Jack Rodriguez.

ASSISTANT: Ok.

USER: Can you please reserve a seat to Washington, IAD?

ASSISTANT: Sure, I am here to help you, may I know your source point?

USER: Las Vegas, LAS is my source point.

ASSISTANT: Could you please help me with your trip dates?

USER: To give a surprise party on the occasion of his birthday, I have to there on 05/19.

ASSISTANT: Please mention your halt restrictions.

USER: I have to return on 05/21. I need to halt in between my journey.

ASSISTANT: Sorry Jack Rodriguez, no flights found on your requested dates.

USER: Ok.

ASSISTANT: Thank you for your information.

USER: Thanks for sharing the information.