var tab_chg = {
	_manual : function (type, num, sum) {
		var max_i = 0;
		var i=0;
		if (type == 'tab') max_i = sum,i=1;
		for (i; i <= max_i; i++) {
			if (i == num) $(type+i).setStyle({'display' : 'block'});
			else $(type+i).setStyle({'display' : 'none'});
		}
	}

}