You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want a book a flight ticket from Houston TX-IAX to meet my friend on his birthday.

ASSISTANT: Sure, please provide your travel dates?

USER: My travelling dates are 03/26 and 03/28.

ASSISTANT: May I know your source point?

USER: My origin point is Houston TX-IAH.

ASSISTANT: Please share your destination?

USER: My landing point is Denver CO-DEN.

ASSISTANT: May I know your name?

USER: I am Ryan Allen.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights running from your source.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you.