You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I made a reservation earlier to attend for a meeting in Houston, due to some problems my meeting venue got changed to San Francisco. Can you please help me to change my existing reservation?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Sure, my name is Joshua Miller.

ASSISTANT: We found a reservation on your name, could you please share me your travel dates?

USER: Sure, My journey dates are from 08/12 to 08/14.

ASSISTANT: Could you please share me your airport codes?

USER: Ok, I would like to start my journey from Houston, TX - IAH. Destination is San Francisco, CA - SFO.

ASSISTANT: How much you can afford for this ticket?

USER: I can afford up to 1000.

ASSISTANT: We found a flight on your details with airline Delta, flight number:1000. Shall I book this ticket?

USER: Sure, you can proceed for booking in Delta airline.

ASSISTANT: Your ticket has been booked.

USER: Thanks for your help.

ASSISTANT: Thank you.