You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Margaret Clark. I am planning to go for ATL from PHL. Can you please help me out by reserving a flight ticket in a best airline?

ASSISTANT: Sure, can I know the travel dates please?

USER: Ok, my travelling dates are 07/07 and 07/09.

ASSISTANT: Sorry, there are no flights available on your dates.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for approaching us.