You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Laura Baker.

ASSISTANT: What help that I can do for you?

USER: I would like to book a ticket to Oakland, can you please help me out?

ASSISTANT: Sure, I will help you. May I know the dates of your travelling?

USER: I am travelling on these dates 02/21 and 02/23.

ASSISTANT: May I know your source and destination airport codes?

USER: I am flying from PHX to OAK.

ASSISTANT: No flights are moving on your dates due to tornado alert, sorry for the trouble.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for your valuable time, have a nice day.