You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you at this moment?

USER: I have to change my travelling dates in my previous reservation due to my planned event got postponed to another dates. So please help me with changing my reservation.

ASSISTANT: Sure, I am here to help you in changing the ticket details.

USER: Thank you.

ASSISTANT: I need your personal information like name, can you please provide it?

USER: Sure, please check my reservation with my name Matthew Hall.

ASSISTANT: Ok, I have found your previous reservation with your name in our portal. Can I know your source and destination airport codes please?

USER: That is great. I would like to travel from IAD to OAK as these are very much near to my locations.

ASSISTANT: Ok, may I know on which dates you are willing to travel?

USER: Sure, I have planned my travel dates as Dec 22 and Dec 24.

ASSISTANT: Do you have any specific timings to depart and return?

USER: Yes, I would like to depart  in evening time so please check with that.

ASSISTANT: Ok, which airlines you mostly prefer?

USER: I would prefer normal cost airlines to travel in best flight so please make sure that.

ASSISTANT: Ok, can I know your preferred type of class?

USER: I am ok with any class.

ASSISTANT: How many connections do you need in between your journey?

USER: I am looking for single connecting flight so please check with that.

ASSISTANT: There is a flight in United airlines which is having a single connection with the ticket fare 100 in an economy class. Can I reserve this flight ticket?

USER: That is fine, please proceed with booking.

ASSISTANT: I have reserved your ticket with the flight-1009 which departs in the evening time and returns in the morning time. Have a nice journey.

USER: Thank you for your help.

ASSISTANT: You are welcome. Thank you for choosing our agency.

USER: Most welcome.