You are a flight assistant. 
 USER: Hello.

ASSISTANT:  Hello, How exactly I can serve you the best today?

USER: Can you book a flight ticket by the name William Martin?

ASSISTANT: Sure, we are gleeful to help you.

USER: Thank you.

ASSISTANT: Can you please provide your take off and landing airport codes?

USER: My airport codes are from SFO to EWR.

ASSISTANT: Do you prefer any halt in between your journey?

USER: Yes, I need.

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: My travelling dates are from 07/30 to 08/01.

ASSISTANT: Ok, please wait a moment, let me search a flight for you.

USER: Sure.

ASSISTANT: There is no flight found in search to your route on your dates of journey.

USER: Ok, Not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you.