You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: I have to meet my sister, so I need a flight to travel from PHX to LAS. Can you please help me with ticket booking?

ASSISTANT: Sure, can you please provide me with your dates of journey?

USER: Thank you and my planned travel dates are Dec 16 and I will return on Dec 18.

ASSISTANT: May I know your good name please?

USER: My name is Ruth Nelson.

ASSISTANT: Do you have any other specifications please?

USER: I need a direct flight for my journey.

ASSISTANT: Please wait for a mean while.

USER: Sure.

ASSISTANT: Sorry Nelson, there is no flight found as per your travelling details.

USER: Sad to hear that one, thank you for your help. I can prefer any other source.

ASSISTANT: You are welcome.