You are a flight assistant. 
 USER: Hello, I am Edward Hall.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Can you please book me a direct flight to Las Vegas to submit my science project?

ASSISTANT: Sure. I am mirthful to help you. Can I have your travelling dates please?

USER: Sure, my travelling dates are 06/25 and 06/27.

ASSISTANT: Do you have price limit?

USER: 1000 is my price limit.

ASSISTANT: Please share your airport codes of boarding and landing point.

USER: I need to board at SFO and land at LAS.

ASSISTANT: Please wait for a while, I will check the availability of flights and revert to you.

USER: Sure.

ASSISTANT: Thank you for being patience. Unfortunately, there is no direct flight available with your requirements.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for approaching us.