You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Deborah Mitchell. Can you help me with booking ticket from LGA to DFW?

ASSISTANT: Sure, please tell me your trip dates.

USER: My planned dates are from 02/17 and 02/19.

ASSISTANT: Ok, please allow me a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no flight on your requested dates.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for choosing us, have a great day.