You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: I am Robert Wilson.

ASSISTANT: How can I help you today?

USER: I would like to travel to Los Angeles, CA - LAX from Philadelphia, PA - PHL.

ASSISTANT: OK, please provide me your travel date?

USER: Sure, On Apr 30 to May 2.

ASSISTANT: Please wait for a moment, I will check and get back to you.

USER: OK.

ASSISTANT: Thanks for waiting, sorry to say there is no any flight available.

USER: Thank you for your information.

ASSISTANT: Thank you.