You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Helen Nelson here.

ASSISTANT: How can I assist you?

USER: I want to book a flight from DEN - DCA, can you help me?

ASSISTANT: Sure, can you share your travel dates please?

USER: I will be travelling from 04/23 to 04/25.

ASSISTANT: Spirit airlines is having a flight with travel charge of 200, shall I proceed for booking?

USER: Ok, please proceed with booking my reservation.

ASSISTANT: Your ticket has been booked with flight-1011, have a safe journey.

USER: Thank you for helping me.

ASSISTANT: Thank you for choosing us.

USER: Most welcome.