You can extend Desheng Li's method further by allowing an iterations count to do multiple flashes like so:

// Extend jquery with flashing for elements
$.fn.flash = function(duration, iterations) {
    duration = duration || 1000; // Default to 1 second
    iterations = iterations || 1; // Default to 1 iteration
    var iterationDuration = duration / iterations;
    
    for (var i = 0; i < iterations; i++) {
        this.fadeOut(iterationDuration).fadeIn(iterationDuration);
    }
}

Then you can call the method with a time and number of flashes:

$("#someElementId").flash(1000, 4); // Flash 4 times over a period of 1 second

You can extend Desheng Li's method further by allowing an iterations count to do multiple flashes like so:

// Extend jquery with flashing for elements
$.fn.flash = function(duration, iterations) {
    duration = duration || 1000; // Default to 1 second
    iterations = iterations || 1; // Default to 1 iteration
    var iterationDuration = Math.floor(duration / iterations);
    
    for (var i = 0; i < iterations; i++) {
        this.fadeOut(iterationDuration).fadeIn(iterationDuration);
    }
    return this;
}

Then you can call the method with a time and number of flashes:

$("#someElementId").flash(1000, 4); // Flash 4 times over a period of 1 second

You can extend Desheng Li's method further by allowing an iterations count to do multiple flashes like so:

// Extend jquery with flashing for elements
$.fn.flash = function(duration, iterations) {
    duration = duration || 1000; // Default to 1 second
    iterations = iterations || 1; // Default to 1 iteration
    var iterationDuration = duration / iterations;
    
    for (var i = 0; i < iterations; i++) {
        this.fadeOut(iterationDuration).fadeIn(iterationDuration);
    }
}

Then you can call the method with a time and number of flashes:

$("#someElementId").flash(1000, 4); // Flash 4 times over a period of 1 second

You can extend Desheng Li's method further by allowing an iterations count to do multiple flashes like so:

// Extend jquery with flashing for elements
$.fn.flash = function(duration, iterations) {
    duration = duration || 1000; // Default to 1 second
    iterations = iterations || 1; // Default to 1 iteration
    var iterationDuration = duration / iterations;
    
    for (var i = 0; i < iterations; i++) {
        this.fadeOut(iterationDuration).fadeIn(iterationDuration);
    }
}

Then you can call the method with a time and number of flashes:

$("#someElementId").flash(1000, 4); // Flash 4 times over a period of 1 second