You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me out?

ASSISTANT: Sure, I will help you. Let me know your name to check for earlier reservation.

USER: Thank you. Sure, my name is Melissa Martinez.

ASSISTANT: Please, standby.

USER: Ok, I will stand.

ASSISTANT: Thank you for waiting, we found a reservation on your name. Can you please provide your journey dates?

USER: Sure, my journey dates are from Nov, 26 to Nov, 28.

ASSISTANT: May I know your boarding and landing airport codes?

USER: Sure, my airport codes are from SFO to IAH.

ASSISTANT: Let me know your connection limit.

USER: Yes, I want a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: Not required.

ASSISTANT: Please, wait for a while.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, there is a flight available with fare 100 and single connection in Spirit airline having 1021 as flight number. Shall I reserve it?

USER: Please proceed with this booking.

ASSISTANT: Your ticket has been confirmed in economy class.

USER: Thank you for your service in booking my ticket.

ASSISTANT: Thank you for choosing us.