You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am David Campbell.

ASSISTANT: How can I assist you today?

USER: I am looking for a flight from IAH to LAX, can you book me a flight ticket please?

ASSISTANT: sure, I am here to help you. Please share your trip dates.

USER: My trip dates are from 07/13 till 07/15.

ASSISTANT: Please wait a moment.

USER: I need a flight with my budget of 300, please check with it.

ASSISTANT: sorry, no flights are available on you request.

USER: That's ok, no problem, Thank you for reaching us.

ASSISTANT: Welcome.