You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you today?

USER: Can you please help me in booking from IAD to OAK?

ASSISTANT: Sure, may I know your good name?

USER: My name is Daniel Smith.

ASSISTANT: When you are willing to travel?

USER: My travelling dates are from Aug 9 to Aug 11.

ASSISTANT: Can I have your connection limit?

USER: I need a connecting flight.

ASSISTANT: Is there any other preferences?

USER: No.

ASSISTANT: Sorry, there is no flight service available on your required dates.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for approaching us.