<select name=s>
</select>
<input type=radio name=r onclick="s.disabled=true">
<input type=radio name=r onclick="s.disabled=false" checked>
</select>
<input type=radio name=r onclick="s.disabled=true">
<input type=radio name=r onclick="s.disabled=false" checked>
function aa()
{
if(document.form.radio.check==true)
document.form.mm.disabled=true;
else
document.form.mm.disabled=false;
}
</script>
<form name=form>
<select name=mm disabled>
<option>111</option>
<option>222</option>
</select>
<input type=radio name=radio onclick=aa()>
</form>