var timer;

function initRoll(){
	timer = setInterval('my_glider.next()',10000);
}

function rollNext(){
	clearInterval(timer);
	my_glider.next();
	timer = setInterval('my_glider.next()',10000);
}

function rollPrevious(){
	clearInterval(timer);
	my_glider.previous();
	timer = setInterval('my_glider.next()',10000);
}