function changeText(){
 var sometextbox = document.getElementById('one').options[document.getElementById('one').selectedIndex].value;
 document.getElementById("hiddenone").value = sometextbox;
}

<form name="sometextbox">
    <select id="one" onchange="changeText()">
       <option value="resalt 1> one </option>
       <option value="resalt 2> two </option>
    </select>
</form>
<input type="hidden" id="hiddenone" value="resalt 1">

<form action="#">
	<input type="radio" value="result 1" name="a" />
	<input type="radio" value="result 2" name="a" />

	<input type="hidden" value="result 1" />
</form>

<script>
	document.forms[0].onchange = function(e) {
		if ( !e.target.closest('input[type=radio]') ) return;

		document.querySelector('input[type=hidden]').value = e.target.value;
	};
</script>