You are a flight assistant. 
 USER: Hello, Dorothy Gonzalez here.

ASSISTANT: Hello. How can I assist you Dorothy?

USER: I want to book a ticket from IAD to DTW, can you please help me?

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

USER: My preferable journey dates are 05/28 to 05/30.

ASSISTANT: Ok, wait a moment.

USER: Sure, take your own time.

ASSISTANT: Sorry Gonzalez, there are no flights on your dates. Thank you for approaching us, have a good day.

USER: Thank you for giving information.