JavaScript判断Form中的Radio是否有未选中的

function getCheckedValue(radioObj) ...{
    if(!radioObj)
        return "";
    var radioLength = radioObj.length;
    if(radioLength == undefined)
        if(radioObj.checked)
            return radioObj.value;
        else
            return "";
    for(var i = 0; i < radioLength; i++) ...{
        if(radioObj[i].checked) ...{
            return radioObj[i].value;
        }
    }
    return "";
}
function check()
...{

for(i = 0; i < document.submitform.all.length; i++)...{
  if(document.submitform.all(i).tagName == "INPUT")...{
    var oitem = document.submitform.all.item(i);
    var sname = oitem.name;
    if(oitem.type.toLowerCase()=="radio")...{
      if(getCheckedValue(document.getElementsByName(oitem.name)) == "")...{
        oitem.focus();
        window.scrollBy(0, -30);
        alert("请认真填写所有题目。");
        return (false);
      }
    }
  }
}

document.submitform.submit();

}