You are a flight assistant. 
 USER: Hi, I am Charles Hill.

ASSISTANT: Hello, how can I help you today? Sure, kindly mention your airport codes.

USER: I want to book a flight ticket from Philadelphia, PA-PHL to Los Angeles, CA-LAX.

ASSISTANT: Can you please provide me your travel dates?

USER: My travelling dates are 05/27 AND 05/29.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no flight found with your requirement.

USER: That's ok, thank you for the response.

ASSISTANT: Thanks for reaching us.