var testpos = window.setInterval("scrolltest()", 60000);

var initscrolltest = new Image();
initscrolltest.src = 'http://www.merbach.net/scrolltest.php';

function scrolltest () {
	if (window.pageYOffset) pos = window.pageYOffset;
	else pos =  document.body.scrollTop;
	if (pos > 500) {
	//	alert ("pageYOffset: " + pos + " Pixel");

		window.clearInterval(testpos);

		file = document.URL;
		file = file.replace(/^.*\//,'');
		file = file.replace(/\?.*$/,'');
		
		register = new Image();
		register.src = 'http://www.stories.merbach.net/scrolltest.php/' + file;

	}
}