You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I render you?

USER: Please help me in booking a flight ticket to Denver, DEN to attend a science festival.

ASSISTANT: Sure, do you have any price limit?

USER: Yes, It must be under 1000.

ASSISTANT: Help me with the planned dates of your travel?

USER: My travelling dates are from 03/20 to 03/22.

ASSISTANT: Where would you like to start your journey from?

USER: From Phoenix, PHX.

ASSISTANT: May I know your name please?

USER: I am Jennifer Roberts.

ASSISTANT: Thank you for your details, we do not find any flights running to your locations.

USER: It's ok. Thank you for the information.

ASSISTANT: Thank you for approaching us.