var dates = [];

function date_switch(emp) {
	var i = emp.id.toString().replace(/:empty$/,'');
	var f;
	if (!dates[i]){
		f = dates[i] = {
			'year'  : $(i + ':year'),
			'month' : $(i + ':month'),
			'day'   : $(i + ':day'),
			'hh'    : $(i + ':hh'),
			'mm'    : $(i + ':mm'),
			'empty' : emp
		};
	}else{
		f = dates[i];
	}
	var dis = f['empty'].checked;
	['year','month','day','hh','mm'].each(function(item){
		f[item].disabled = dis;
	});
	return;
}