curpos = 1;
nextpos = 2;

function showrollcontent(pos) {
	for(a=1; a < rollcons+1; a++) {
		if(a != pos) {
			document.getElementById('rolllink'+a).setAttribute('class', 'inactive');
			document.getElementById('rolllinkbox'+a).setAttribute('class', 'inactive');
			document.getElementById('rollcontent'+a).style.display = 'none';
		}
	}

	document.getElementById('rolllinkbox'+pos).setAttribute('class', 'active');
	document.getElementById('rolllink'+pos).setAttribute('class', 'active');
	document.getElementById('rollcontent'+pos).style.display = 'block';

	curpos = pos;
	if(curpos == rollcons) {nextpos = 1;}
	else {nextpos = curpos+1;}
}

function setint() {
	rollint = window.setInterval('showrollcontent(nextpos)', 5000);
}

function clearint() {
	window.clearInterval(rollint);
}

setint();