You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Melissa Roberts here.

ASSISTANT: How may I assist you?

USER: Can you please check for the flights on the route from IAD airport to Oakland?

ASSISTANT: Sure, please share your desired dates with me.

USER: My journey will start on June 9th and I will return on June 11th.

ASSISTANT: May I know your return time?

USER: My return time is in the evening.

ASSISTANT: Do you need a connecting flight?

USER: Yes, please check for 1 connection flight.

ASSISTANT: Sorry to say, there is no flight available for your journey.

USER: Oh! That's sad to know. Anyways, thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: Most welcome.