You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Thomas Martin. Due to postpone of my interview, I want to change my existing reservation. Could you help me?

ASSISTANT: Ok, I am glad to help you.

USER: Ok.

ASSISTANT: Could you please provide me your airport codes?

USER: Sure, my starting point is from Houston,TX - HOU. My destination airport is Washington DC - DCA.

ASSISTANT: Can you please share me your travelling dates?

USER: Ok, my journey dates are 12/05 and 12/07.

ASSISTANT: Do you have any other specifications?

USER: Yes, I spend up to 5000 and I need a connecting flight.

ASSISTANT: There is a flight found with flight number:1010 and airline: southwest.

USER: Ok, proceed to book.

ASSISTANT: Shall I proceed with the booking? Your booking has been confirmed.

USER: Thank you.

ASSISTANT: Thank you for reaching us.