You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a flight ticket from LAX to DEN?

ASSISTANT: May I know your travel dates?

USER: Ok, please book a ticket for the dates July 26th and July 28th.

ASSISTANT: Do you have any connection preferences? May I know your name please?

USER: The planned flight limit is single. My name is Timothy Anderson.

ASSISTANT: No flights found as per your preferences.

USER: Thank you for the help.

ASSISTANT: Thank you for choosing us.