You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Johnson.

ASSISTANT: How may I assist you today?

USER: I want to book a flight ticket from LAS to EWR. Could you help me in booking?

ASSISTANT: Sure, please mention your travelling dates?

USER: My travelling dates are from April 09-11.

ASSISTANT: Do you need any specifications for this reservation?

USER: My return date should be in the evening and I need connecting flight.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there are no flight tickets available with your travelling dates.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for reaching our service.