You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Debra Davis here. I would like to book a ticket from OAK to HOU.

ASSISTANT: May I know your trip dates?

USER: My travel dates are as follows Aug 09 and Aug 11.

ASSISTANT: Do you prefer any specifications?

USER: I would like to board a single connection flight with return in the evening.

ASSISTANT: Sorry to inform you that unfortunately there is no flights available by the given details.

USER: No issue, thank you for the information.

ASSISTANT: Thank you.