You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Can you help me to book a flight ticket from DFW to PHL?

ASSISTANT: Sure, may I know the planned travel dates?

USER: My travelling dates are 24 to 26 of May.

ASSISTANT: Please provide me the specifications.

USER: I would like to travel in normal cost with a connecting flight.

ASSISTANT: May I know the name?

USER: I am Mark Phillips.

ASSISTANT: Sorry, there are no flights are available for your desired intent.

USER: It's ok, not a problem. Thank you.

ASSISTANT: Thank you for reaching us.