How to load a JS function every 1000px when scrolling down a page?

How to load a JS function every 1000px when scrolling down a page?

sory sory my english
When I am scrolling down a page, how do I load a JS function every 1000px?
This is the call of the function that I want to load:
refresh('refresh_status', 'refresh_status.php', '', '', '', 'refresh');