You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jessica Campbell.

ASSISTANT: Jessica Campbell, how may I assist you with today?

USER: I want to book a flight ticket from PA-PHL to NV-LAS. Can you help me?

ASSISTANT: Sure, I will help you by booking your flight ticket. Please help me with your departure and return journey dates.

USER: I would like to my journey on aug 25th and my return will be at  aug 27th.

ASSISTANT: Thank you, for the information. Please allow me a minute while I work on it.

USER: Sure.

ASSISTANT: Thank you for waiting. I am sorry to inform you that there are no flights available on the given dates.

USER: No issue.I will choose other alternative. Thank you for the information.

ASSISTANT: Thank you for understanding. Have a great day!.