You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I'm Benjamin Campbell. I am planning to travel from LAX to IAH for a business trip. Can you please help me with booking a flight ticket?

ASSISTANT: Sure. Can I know your trip dates?

USER: Sure, my departure date is on 07/27 and the return date is on 07/29. Please make sure that the price limit should not exceed 1000.

ASSISTANT: Sorry, no flight is there.

USER: That's really sad. Anyways, thank you for your help.

ASSISTANT: You are most welcome.