You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you?

USER: Could you please help me to book an economy class ticket within the fare limit 2000 to New York?

ASSISTANT: Sure, may I know your travelling dates?

USER: I need to depart on 03/05 and my return date will be on 03/07.

ASSISTANT: Let me know your name.

USER: I am William Williams.

ASSISTANT: Kindly share your source and destination code.

USER: My boarding and landing points are IAH and LGA.

ASSISTANT: Thanks for the information, please wait for a minute.

USER: Sure.

ASSISTANT: Thanks for your valuable time, there is no flight available with your requirements.

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

ASSISTANT: Have a good day.