You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Actually, I want to change my existing reservation due to some health issues, can you please help me in this?

ASSISTANT: Sure, may I know your name please to check the reservation status?

USER: Ok, my name is Gregory Robinson.

ASSISTANT: I found a reservation with your details. Please provide me your journey dates.

USER: It is very happy to say, my date of journey is from 10/25 to 10/27.

ASSISTANT: May I know your respective airport codes please?

USER: Sure, my respective airports codes are from ORD to HOU.

ASSISTANT: Please give me a minute.

USER: Sure, take your time.

ASSISTANT: Robinson, I found a flight with JetBlue airlines available with price 200. Shall I book the ticket for you?

USER: Ok, please proceed with the changing of my reservation.

ASSISTANT: Your ticket is confirmed and the flight number is 1000.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.