You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Steven Baker here.

ASSISTANT: How may I help you?

USER: I want to travel from Philadelphia to Houston. Can you please help me for booking the flight ticket?

ASSISTANT: May I know your travel dates?

USER: My departure date is 12/20 and return date is 12/22.

ASSISTANT: Please help me with your airport codes.

USER: My airport codes are from PHL to IAH.

ASSISTANT: Sorry, there is no flight found basis on your details.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.