function formatSize(size) {
    var i = 0,
        base = 1024,
        prefixes = ' KMGTPEZY';

    if (size < 1) {
        return '0';
    }
    else if (size >= base) {
        i = Math.floor( Math.log(size) / Math.log(base) );
        if (i >= prefixes.length) return 'n/a';
        size = ( size / Math.pow(base, i) ).toFixed(2) * 1 + ' ';
    }

    return size + prefixes[i] + 'B';
}