You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Helen Davis.

ASSISTANT: Ok.

USER: I want to book a flight ticket to New York, please help me out.

ASSISTANT: Ok, may I know your airport codes?

USER: I want to fly from LAS to EWR.

ASSISTANT: Please share your planned journey dates.

USER: My travelling dates are from 07/19 to 07/21.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, no flights found with your given dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.