You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am planning to go for hummer tour with my friends at Las Vegas, LAS. Could you please reserve a ticket with fare 5000?

ASSISTANT: Sure, May I know the source code?

USER: My boarding point is Denver, DEN.

ASSISTANT: Please help me with your trip dates.

USER: My planned dates for this trip are from 04/30 to 05/02.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Can I get your name?

USER: My name is Shirley Phillips.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.