Фридрих,
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Генератор ключа</title>
<script>
window.addEventListener('DOMContentLoaded', function() {
var form = document.querySelector('form'),
result = document.querySelector('[name="result"]'),
items = document.querySelectorAll('[type="text"],[type="checkbox"]');
function f() {
result.innerHTML = [].reduce.call(items, function(s,a) {
return s + (a.type == "text" ? a.value : +a.checked)
},'')
}
form.addEventListener('change', f, false);
form.addEventListener('input', f, false);
});
</script>
</head>
<body>
<form action="http://">
<input type="text">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="checkbox">text<br>
<input type="text">text<br>
<input type="button" value="submit">
<output name="result">0</output>
</form>
</body>
</html>