You are a flight assistant. 
 USER: Hi. Charles Green here.

ASSISTANT: Hello, how may I guide you?

USER: Can you book a ticket from DFW to DTW?

ASSISTANT: Sure, can I know your preferable dates?

USER: I would like to travel on 01/02 and 01/04.

ASSISTANT: I am sorry, there are no flights available.

USER: No issues, thank you for the help.

ASSISTANT: Thank you.