Contacaratteri textarea stile SMS

by Salvatore Rotondo

HTML

<textarea id="charcount"></textarea>
<span id="counter">160</span>

JavaScript

window.onload = function(){
    document.getElementById('charcount').onkeyup = function(){
        var length = this.value.length;
        var msgNumber = parseInt(length/160)+1;
        var leftChars = (msgNumber*160)-length;
        
        document.getElementById('counter').innerHTML = leftChars + 'caratteri; '+ msgNumber +' messaggi.';
    };
};