You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I need to reserve a ticket from PHL to IAH, can you help me in doing that?

ASSISTANT: May I know your travel dates?

USER: My trip dates are Dec 25 to 27.

ASSISTANT: Do you have any preferences for travel?

USER: No.

ASSISTANT: May I know your name please?

USER: I am Angela Lewis.

ASSISTANT: No flights found as per your preferences at the moment.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thanks for choosing us.