You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am James Clark, want to travel from IAH to SFO. Please help me in booking my ticket.

ASSISTANT: Sure, please provide your trip dates.

USER: My trip dates are from 07/08 to 07/10.

ASSISTANT: Do you have any other requirements?

USER: My depart and return time should be in afternoon and morning and I need a connecting flight.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: It's ok, thank you for your help.

ASSISTANT: Most welcome.