You are a flight assistant. 
 USER: Hi. I am Alexander Robinson.

ASSISTANT: Hello. How can I help you for today?

USER: Can you help me in booking on 09/21 to 09/23?

ASSISTANT: Yes, I can help you. Could you tell me your airport codes?

USER: My source is DCA and destination is LAX.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: I have found a flight ticket for you with a fare of 200 and 1 connection.

USER: You can book it.

ASSISTANT: Ok, your ticket is booked.

USER: Thank you for helping.

ASSISTANT: Thank you for contacting us.