You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: William Campbell here.

ASSISTANT: How may I assist you?

USER: Can you make my reservation from DCA to PHL?

ASSISTANT: Sure, Please provide me your trip dates.

USER: My travelling dates are from 08/07 to 08/09.

ASSISTANT: Sorry Campbell, no flights available in your route.

USER: It's ok. Thank you for your help.

ASSISTANT: Thank you for reaching us.