You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I be your helping hand?

USER: I need a direct flight to Las Vegas for attend my brother birthday. Can you please book a flight ticket from TX - DFW?

ASSISTANT: Sure, we are gleeful to help you. Please share your dates of journey?

USER: 11/18 and 11/20 are my travelling dates.

ASSISTANT: Kindly mention your destination?

USER: My destination is NV - LAS.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for your precious time. Unfortunately there are no flights found.

USER: Ok, no issues.

ASSISTANT: May I know your name?

USER: Kathleen Lee is my name.

ASSISTANT: Thank you for opting our service. Have a wonderful day.

USER: Thank you for your information.