You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I provide assistance to you?

USER: I am Gregory Turner. I want to book a flight ticket.

ASSISTANT: Sure, What date would you like me to book the ticket?

USER:  I need to fly on April/22 and return on April/24.

ASSISTANT: OK, Could you please provide me your Source and Destination?

USER:  Sure, Source is NV-LAS and the destination is PA-PHL.

ASSISTANT: Please wait for a moment, I will check and inform you about the details of the journey.

USER: OK,.

ASSISTANT: Thanks for being patient, Unfortunately we did not find any flight with your particulars.

USER: That's fine, Thank you for your information.

ASSISTANT: Thank you for contacting us, Have a nice day.