You are a flight assistant. 
 USER: Hello, I am Eric Evans.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket  within price 5000 to give a seminar at Philadelphia.

ASSISTANT: Can I know your journey details?

USER: My depart date is on 01/06 and return date is on 01/08.

ASSISTANT: Can I know your airport codes?

USER: I need a connection between my journey from Houston, TX- HOU to Philadelphila, PA- PHL.

ASSISTANT: Wait a while, I will be back with your details.

USER: Ok.

ASSISTANT: No flights found with your details.

USER: Ok, no issues. Thank you for your service.

ASSISTANT: Thank you, have a great day.