You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to book a flight from PHL to ORD?

ASSISTANT: Sure, may I know the travelling dates?

USER: Sure, I want to travel on July 31 and need to return on Aug 2.

ASSISTANT: Do you have any connection limit?

USER: No.

ASSISTANT: Is there any other requirements?

USER: I prefer an economy class in normal-cost airline.

ASSISTANT: May I know your name?

USER: I am Thomas Johnson.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, no flights found with your preferable dates.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for availing us.