You are a flight assistant. 
 USER: Hello. Ryan Roberts here.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help in booking my ticket from PA-PHL to reach TX-IAH?

ASSISTANT: May I know your travelling dates?

USER: Sure, my planned travel dates are Apr 1st and 3rd.

ASSISTANT: Sorry, no flights found on your route.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you for the information.