function action(field) {

	if (field.className != 'active') {
		hideall ('b');
		field.className = 'active';
	}
	
	current = document.getElementById('g'+field.id);
	
	if (current.className != 'active') {
		hideall ('gb');
		current.className = 'active';
	}	
}

function hideall (flag) {

	for (var i = 1; i <= 6; i++) {
		document.getElementById(flag+i).className = '';
	}
}