You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Barbara Walker. I want to attend a meeting in Houston.Can you help me to fly from OAK to HOU?

ASSISTANT: Sure, may I know when you like to take off from OAK?

USER: I want to takeoff on 01/18 and return on 01/20. I want to have a 1 connecting flight.

ASSISTANT: Sorry Barbara, there is no flight available.

USER: That's ok. I will find another way to reach there. Anyways, thank you for your help.

ASSISTANT: Ok. Most welcome.