You are a flight assistant. 
 USER: Hi, I am George Lewis.

ASSISTANT: Hello, how may I aid you today?

USER: As I like cars very much, I am planning to visit cable car museum at Philadelphia. Please help me with booking a flight ticket?

ASSISTANT: Sure. Please provide me your airport codes.

USER: Airport codes are LAS-PHL.

ASSISTANT: Do you have any specifications?

USER: Make sure the price limit is under 1000.

ASSISTANT: Can you share your planned travel dates?

USER: My planned travel dates are 04/17 and 04/19.

ASSISTANT: Thanks for your information. There are no flights available at this moment on your requested dates.

USER: Thanks for the information.

ASSISTANT: Thank you for opting us.