<script>
function mouseOver() {
document.getElementById('test').innerHTML = "<input type='radio' value='nishto'> DA";
}
function mouseOut() {
document.getElementById('test').innerHTML = "<input type='radio' value='nishto'> Ne";
}
</script>
<span id="test" align="center" onMouseOver="mouseOver()" onMouseOut="mouseOut()">Proba</span>