JQuery persistent forms

/**
* This is an example to create persistent forms using 
* HTML5 localStorage + jQuery serialization and
* url.decode from http://www.webtoolkit.info/
*
*
* The example bellow is seriously unoptimized. 
* It listens to changing events in the form and
* serializes the data of the form in localStorage
*/

$(':input').change(function(){
    localStorage.form = $(this).parents('form').serialize();
});
if (localStorage.form){ //populate the form if the page was refreshed
    unserialize(localStorage.form);
}

/**
*
*  URL encode / decode
*  http://www.webtoolkit.info/
*
**/
function url_decode(utftext) {
    utftext = unescape(utftext)
    var string = "";
    var i = 0;
    var c = c1 = c2 = 0;
    while ( i < utftext.length ) {
        c = utftext.charCodeAt(i);
        if (c < 128) {
            string += String.fromCharCode(c);
            i++;
        }
        else if((c > 191) && (c < 224)) {
            c2 = utftext.charCodeAt(i+1);
            string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
            i += 2;
        }
        else {
            c2 = utftext.charCodeAt(i+1);
            c3 = utftext.charCodeAt(i+2);
            string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
            i += 3;
        }
    }
    return string;
}

function unserialize(data){
    var rows = data.split('&');
    $.each(rows, function(i, row){
        var field = url_decode(row).split('=');
        var field_el = $(':input[name='+ field[0] +']');
        /**
        * Other input types must be verified
        */
        if(field_el.attr('type') == 'checkbox'){
            field_el.attr('checked', field[1]);
        }else{
            field_el.val(field[1]);
        }
    })
}