You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Janet Taylor here.

ASSISTANT: How may I help you?

USER: I want to visit my friend's new hotel to look after his business for a day in his absence, can you please book a flight ticket from PHL - DEN?

ASSISTANT: Sure Taylor, I am here to help you. When you are willing to travel?

USER: My travelling dates will be from 04/13 to 04/15.

ASSISTANT: Just a moment.

USER: Sure.

ASSISTANT: Taylor, sorry to inform that no flights are available on your prefer dates.

USER: Oh! That's fine, thank you for checking anyways.

ASSISTANT: You are welcome.