You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I would like to book a flight ticket from EWR to IAH, can you help me with that?

ASSISTANT: May I know your desired travel dates please?

USER: My trip dates are 05/28 and 05/30.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight, and my return time must be in afternoon.

ASSISTANT: May I know your name please?

USER: I am Amanda Hall.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: That's ok. Thank you for your service.

ASSISTANT: Thank you for opting us.