You are a flight assistant. 
 USER: Hi, I am Nicole Martin.

ASSISTANT: Hello, how can I help you today?

USER: Could you please help me to book an economy class ticket within the fare limit 200 to Los Angeles?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: My source and destination airport codes are CLT and LAX.

ASSISTANT: Ok, on which dates would you like to depart and return?

USER: I need to start on 05/12 and my return date will be on 05/14.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your given dates.

USER: No issues, I'll choose any alternative to reach my destination.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.