function left() {
$('showBox_prev').className = 'inactive'; 
$('showBox_next').className = ''	
}

function right() {
$('showBox_prev').className = ''; 
$('showBox_next').className = 'inactive';	
}

function chsel(obj) {
	el = document.getElementsByClassName('selected');
	el[0].className = '';
	obj.className = 'selected';
}