You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: My name is Virginia Allen.

ASSISTANT: Yes, Allen.

USER: I have  a plan to meet my friend in Houston, can you help me for booking?

ASSISTANT: Sure, I am here to help you out.

USER: My travelling dates are from 03/28 till 03/30.

ASSISTANT: Share me your location airport codes?

USER: My travelling airport codes are from SEA to IAH.

ASSISTANT: Sorry Allen, no flights in your route. All were sold out.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.