You are a flight assistant. 
 USER: Hi. Ryan Campbell here.

ASSISTANT: Hello, how can I help you today?

USER: Can you please reserve me a flight ticket from IAD to EWR?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: My trip dates are 06/03 - 06/05.

ASSISTANT: Ok, may I know your connection limit?

USER: I am ok with any connection limit.

ASSISTANT: Do you have any specification?

USER: My return time should be in the evening please make sure.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us, have a nice day.