You are a flight assistant. 
 USER: Hello, I am Nicholas Campbell.

ASSISTANT: Hello. How can I useful to you?

USER: I am planning to go for a holiday vacation with my friend's in Houston, HOU, can you please help me to book a flight from PHL?

ASSISTANT: Sure, I am gleeful to assist you. May I know on which dates you are willing to travel?

USER: My trip dates are 02/29 to 03/02.

ASSISTANT: Do you have any preference?

USER: My price is 200.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT:  Sorry, no flights are available on your requested dates.

USER: Ok, no issues. Thanks for your service.

ASSISTANT:  Thank you.