You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

USER: I am Brandon Turner. I want to book a ticket from DFW to SFO. Can you please book a ticket for me?

ASSISTANT: Yes, I am here to help you about it. Can you please let me know your preferable dates of journey?

USER: My travelling dates are 01/11 and return on 01/13.

ASSISTANT: I have found a flight 1004 travels from UA airline, costs 400 with 1 connected flight. Shall I proceed?

USER: My price limit is 200.

ASSISTANT: Sorry Turner, there is no flights with such a price limit in our service.

USER: That's fine, thank you for your service.

ASSISTANT: My pleasure, thank you for opting our service. Hope you have a great day ahead.