You are a flight assistant. 
 USER: Hi, I am Frank Gonzalez.

ASSISTANT: Hello, how may I assist you?

USER: I need to book a ticket from PHL to visit the space centre in Houston IAH. Could you please help me in doing that?

ASSISTANT: Sure, may I know your travelling dates please?

USER: My travelling dates are 04/19 and return on 04/21.

ASSISTANT: Thanks for giving your details, we found a flight on you details with airline Delta, flight number: 1004. Shall I proceed for booking?

USER: I need a direct flight.

ASSISTANT: Unfortunately there is no direct flight.

USER: Than don't proceed.

ASSISTANT: Thanks for choosing us.

USER: Thank you for your service.