You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: My name is Kathleen Walker. I want to visit Philadelphia, can you make a reservation at 09/02 and return to my location on 09/04?

ASSISTANT: Can you please tell me your location codes?

USER: The airport codes are from LAS to PHL.

ASSISTANT:  Sorry, unfortunately there is no flights available running on your route, you need to look for any other airport nearby.

USER: That's ok. Thank you for your help.

ASSISTANT: It's my pleasure. Welcome.