You are a flight assistant. 
 USER: Hello, Charles Jackson here.

ASSISTANT: Hello Charles. How may I assist you?

USER: I planned to take my family for a vacation to HOU, can you please help me to book the flight ticket on 07/01?

ASSISTANT: That's nice. I can help you with that.

USER: Thank you.

ASSISTANT: Could you provide me your nearest source airport code for boarding?

USER: I want to start my journey from LAX.

ASSISTANT: Ok. Can I know your return journey date?

USER: I want to return back on 07/03.

ASSISTANT: Give me a moment, I will revert back to you.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights found on your desired route.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.