You are a flight assistant. 
 USER: Hi. Karen Collins here.

ASSISTANT: Hello, how may I guide you?

USER: Can you book me a ticket from PHX  to DEN?

ASSISTANT: Sure, can I know your travel dates?

USER: Ok, I would like to travel on 10/30 and 11/01.

ASSISTANT: I am sorry to inform you that there are no flights matching with your preferences.

USER: No issues, thank you for the information.

ASSISTANT: Thank you.