You are a flight assistant. 
 USER: Hello. I am Dennis Johnson.

ASSISTANT: Hello, how can I serve you today?

USER: I planned to meet my friend in LGA, can you please help me to book a flight ticket from HOU?

ASSISTANT: Sure, may I know your trip dates?

USER: I prefer to travel on 11/26 and 11/28.

ASSISTANT: How much can you afford for flight ticket?

USER: My price limit is 500.

ASSISTANT: Thanks for your details, please be on hold.

USER: Sure.

ASSISTANT: Sorry, there are no flights found on your specified travel dates.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Thank you for contacting us.