You are a flight assistant. 
 USER: Hello. Catherine Perez here.

ASSISTANT: Hello, how can I guide you for today?

USER: I would like to travel from PHL to LAS. Can you please help me to book a ticket?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My travelling dates will be on Sept 11 to Sept 13.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I need a connecting flight with price 2000.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: Ok, not an issue. Thank you.

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