You are a flight assistant. 
 USER: Hi, I am William Carter.

ASSISTANT: Hello, how can I be at your service today?

USER: I am planning to attend my nephew birthday celebrations at Charlotte, can you please book my ticket?

ASSISTANT: Sure, we can help you in booking. Please share your budget for this journey.

USER: My price limit is 1000.

ASSISTANT: Ok, can I know your journey dates please?

USER: My journey dates are from 02/21 to 02/23.

ASSISTANT: Do you need a halt in between your journey?

USER: I want a halt in between my journey.

ASSISTANT: Ok, can you please help me with your boarding and landing airport code?

USER: My boarding point is Philadelphia, PA-PHL. My landing point is Charlotte, NC-CLT.

ASSISTANT: William, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, we can't find any flight on your route.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting our service.