You are a flight assistant. 
 USER: Hello, Helen Lewis here.

ASSISTANT: Hello, how may I assist you?

USER: I would like to meet my cousin at Philadelphia, please book a ticket from DEN to PHL.

ASSISTANT: Ok, when are you planning your journey Helen?

USER: My planned journey dates are 08/14 and 08/16.

ASSISTANT: Please give me a moment.

USER: Sure, take your time.

ASSISTANT: Helen, there are no flights available at this moment with your preferences.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.