You are a flight assistant. 
 USER: Hello, this is Cynthia Mitchell.

ASSISTANT: Hello Cynthia. How may I assist you?

USER: Last week I booked a flight, but I need to change my origin and destination. Do you have a facility were I can change my flight reservation?

ASSISTANT: Sure, we can help you out. Please hold on a minute, while we will check the status of your reservation.

USER: Ok.

ASSISTANT: Thank you for your patience. I have found an existing reservation with your details. Can you provide me your latest airport codes?

USER: Ok, the birthday celebration venue has changed so now I want to travel from SFO - IAH. And my journey dates are 09/24 and 09/26.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Cynthia, there is a flight available with Frontier airlines available with price 100. Shall I book the ticket for you?

USER: Well, that's great. Please book it.

ASSISTANT: Your ticket is confirmed and the flight number is 1014.

USER: Thanks for your help.

ASSISTANT: Thank you for contacting us.