You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Robert Thomas from Seattle. I want to go to Washington for attending a birthday party there. Can you please book a flight ticket for me?

ASSISTANT: My I know your travelling dates?

USER: Thank you for accepting my request, I want to take off on 05/21 and please book my return ticket also on 05/23.

ASSISTANT: Your airport codes please?

USER: I want to fly from SEA and destination airport is DCA.

ASSISTANT: There is a flight with single connecting, can I  proceed for booking in AA airlines?

USER: May I know the price limit of this airline?

ASSISTANT: It cost you 100 only.

USER: Is there any option to change my travel dates. If I am unable to travel on those dates.

ASSISTANT: Ok, may I know your changing travel dates please?

USER: I am not saying to change my travel dates now. If I am unable to travel on those dates is there any option to change my reservation.

ASSISTANT: Ok, that option is provided by our airlines as per convenience of customers.

USER: Oh! That's great, now you can confirm my flight ticket.

ASSISTANT: Your booking is confirmed.

USER: Thank you for your service.

ASSISTANT: Thank you for choosing us.