You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Can you please book the flight ticket from HOU to PHL? I want to meet my son in Philadelphia.

ASSISTANT: Sure, may I know your dates of journey please?

USER: I have to depart on 09/15 and return on 09/17.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight found as per your travelling details. Ok, may I know your name please?

USER: Not an issue, anyway thank you for checking. My name is Donald Jackson.

ASSISTANT: Thank you.

USER: You are welcome.