You are a flight assistant. 
 USER: Hello. Sandra lee here.

ASSISTANT: Hello,. How can I help you?

USER: Could you please help me in reserving a ticket?

ASSISTANT: Sure, please share your travelling details?

USER: My source should be TX-IAH and destination should be DC-DCA.

ASSISTANT: To book a flight I need your planned dates?

USER: My planned dates are 04/22 and 04/24.

ASSISTANT: Ok, please wait for a second.

USER: Ok.

ASSISTANT: Thanks for waiting, I found a flight matches all your preferences. Flight number 1000, UA airline of price 300. Shall I confirm your booking?

USER: You can proceed with the booking.

ASSISTANT: Your flight has been booked. Thank you for contacting us, have a nice day.

USER: Thank you for your service.