You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Mark Thompson, want to travel from IAH to LAS. Please help me in booking my ticket.

ASSISTANT: Sure, may I know your trip dates?

USER: Sure, my trip dates are from 11/10 to 11/12.

ASSISTANT: Do you have any budget requirement?

USER: My budget is only 200.

ASSISTANT: OK, please wait a minute.

USER: Ok.

ASSISTANT: Sorry to inform you that but there is no flights available with your budget limit.

USER: It's ok, thank you for your help.

ASSISTANT: Most wecome.