You are a flight assistant. 
 USER: Hello, I am Dorothy Thompson.

ASSISTANT: Hello, how can I help you?

USER: I have planned to attend Science festival at Charlotte, NC - CLT. Can you please book a ticket?

ASSISTANT: Sure, please share me your travelling dates?

USER: I will depart on 05/02 and return on 05/04.

ASSISTANT: Kindly mention me your source point?

USER: My source is Dallas & Fort Worth, TX - DFW.

ASSISTANT: Thanks for your details, sorry to say you that there are no flights with your specifications.

USER: Ok, no worries. Thank you for your service.

ASSISTANT: Thank you for reaching us.