You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I help you?

USER: I am Margaret Martin. I have a plan to celebrate the nature festival with my granny to explore the nature in Dallas & Fort worth.Could you please avail me in booking a flight ticket with fare 1000?

ASSISTANT: Sure, May I know the journey codes?

USER: My journey codes are from NV-LAS to TX-DFW.

ASSISTANT: Please help me with your travel dates.

USER: I would like to depart on 12/17 and arrive on 12/19.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you for opting us.