function start(x) {

	var y = x;
	var t =  y - 2;

	//window.alert(y)

	if (y > 1) {

		var year = document.getElementById(t);
		//window.alert(t);
		year.className='intro_dates_highlighted';

		if (y <= 2 || y == 15) {
			var year2 = document.getElementById('15');
			year2.className='intro_dates';
		}

		var p = t;

		if (p >= 1) {
			var s =  p - 1;
			var prev = document.getElementById(s);
			prev.className='intro_dates';
		} // fi


	} // fi

} // f-n