SO - 15291138

HTML

<div>
    <textarea maxlength=5></textarea>
</div>
<span></span>

JavaScript

$('textarea').live("keyup", function(event) {
    textareaCounter(this, event);
}); 

textareaCounter = function(element, evt) {

    //Get char limit
    var limit = $(element).attr("maxlength");

    // get current character count
    var current = $(element).val().length;

    // if current character count is greater than or equal to the character limit
    if(current >= limit) {
        // prevent further characters from being entered apart from the 
        // Delete and Backspace keys
        if(evt.which != 0 && evt.which != 8)
        {
            if (evt.preventDefault) {
                evt.preventDefault();
            }
            else {
                evt.returnValue = false;
            }
        }
    }

    // add the remaining character count to our span
    $(element).parent().next().show().text( current + " / " +  limit);
}