[jkr]

jkr,
Однотипных - по какому признаку?

Как-то так:

<input type="checkbox" id="protection1" value="value1">
<input type="checkbox" id="protection2" value="value2">
<input type="checkbox" id="protection3" value="value3">
<input type="checkbox" id="protection4" value="value4">
<input type="checkbox" id="protection5" value="value5">
	<script>
	document.getElementById('protection').onchange = function submitprotection() {
		var artikul = document.getElementById('artikul');

		artikul.value += this.checked ? protection.value : '';
	}
</script>
<input type="text" id="artikul">