You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I need to visit National air and space museum in Washington. Can you book me a flight ticket?

ASSISTANT: Sure, is there any restrictions on connection limit?

USER: I need one connection limit.

ASSISTANT: Let me know your good name please.

USER: Matthew Walker is my name.

ASSISTANT: May I know your airport codes?

USER: My airport codes are TX - IAH to DC - DCA.

ASSISTANT: When do you want to travel?

USER: I need to travel on 05/23 and return on 05/25.

ASSISTANT: Please wait a moment. Let me check and get back to you.

USER: Ok.

ASSISTANT: Thanks for your time. Unfortunately there is no flight available with your requirements.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you and have a nice day.