You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am David Smith, I would like to change my recent reservation, can you help me to change that reservation because of some work?

ASSISTANT: Sure, please wait a moment I will check your complete reservation details and proceed further.

USER: Thank you for your quick response, I will wait for your response.

ASSISTANT: Ok, I found a reservation on your name. Could you please provide your new airport codes?

USER: Sure, I would like to travel from DEN to LGA.

ASSISTANT: May I know your airport codes on which route you want to travel?

USER: My trip dates are 04/15 and 04/17.

ASSISTANT: Ok, please wait a moment I will check for the available flights on your dates.

USER: Sure, take your own time.

ASSISTANT: Ok, there is a flight 1003 in Spirit airline matching your details with price 200. Shall I proceed?

USER: You can proceed with this flight.

ASSISTANT: Ok, your booking is done.

USER: Thanks for your help.

ASSISTANT: You are welcome, have a safe journey.