[Dmitriyff]

var mousedown = function() {
		var smenaFonaSetki = $(this).attr("class");
		if (smenaFonaSetki=='my_class') {
			$(this).removeClass('my_class').addClass('blackZone');
		}
		else {
			$(this).removeClass('blackZone').addClass('my_class');
		}

		$(this).on('mouseover', mouseover)
		       .on('mouseup', mouseup);
	},
	mouseover = function() {
		var smenaFonaSetki = $(this).attr("class");
		if (smenaFonaSetki=='my_class') {
			$(this).removeClass('my_class').addClass('blackZone');
		}
		else {
			$(this).removeClass('blackZone').addClass('my_class');
		}
		
	},
	mouseup = function() {
		$(this).off('mouseover')
		       .off('mouseup');
	};

$('td').on('mousedown', mousedown);