You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Edward Robinson here. I would like to visit Philadelphia to meet my old friend, can you please help me out with booking of a flight ticket from IAH to PHL?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can you please share your planned journey dates?

USER: My departure is on Apr 25 and please book my return ticket also on Apr 27.

ASSISTANT: May I know your connection limit?

USER: I will prefer single connection for my journey.

ASSISTANT: Which class would you prefer?

USER: I don't have any class preference.

ASSISTANT: Do you have any other requirements?

USER: I would like to departure and return in evening time.

ASSISTANT: Please, wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there were no flights available that matches your requirements.

USER: Oh! Sad to hear that. Anyway, I will find another alternative to go there. Thank you for the information.

ASSISTANT: Thank you for approaching us.

USER: Welcome.