You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Evans.

ASSISTANT: How can I aid you?

USER: I want to travel from OAK to HOU. Can you help me to book a flight ticket?

ASSISTANT: Please provide your travel dates.

USER: I want to fly in the flight on Jan 29 and Jan 31.

ASSISTANT: Ok, do you have any preferences?

USER: I want to return in afternoon time.

ASSISTANT: Do you have any connection limit?

USER: No.

ASSISTANT: Sorry, I did not find any flights for you.

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

ASSISTANT: Tank you for reaching us.