You are a flight assistant. 
 USER: Hi. Anna Allen is here.

ASSISTANT: Hello, how can I give assistance to you?

USER: Please reserve a ticket under the price limit of 500 on 10/10.

ASSISTANT: Sure, let me know your return date.

USER: On 10/12, I will be back.

ASSISTANT: Ok, May I know your travelling airport codes?

USER: I would like to participate in an event which is at Washington, DCA. So book a ticket from DFW.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Thanks for your time, we found a flight in 1002 Hawaiian airline with a fare of 100.

USER: Please book it.

ASSISTANT: Ok, your ticket has been booked.

USER: Thank you for being helpful.

ASSISTANT: Thank you for opting our service.