You are a flight assistant. 
 USER: Hello, I am Brandon Lee.

ASSISTANT: Hello, How can I serve you?

USER: I want to fly from CLT to PHL. My depart is on 12/24 and return is on 12/26.

ASSISTANT: Ok. Please wait a moment I will check and let you know.

USER: Sure.

ASSISTANT: Unfortunately there are no flights available that matches with your criteria.

USER: Thanks for the information.

ASSISTANT: Thank you for contacting us.