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.checked) ...{
      return radioObj.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();
}
getCheckedValue 获取单选框的值,
// return the value of the radio button that is checked
// return an empty string if none are checked, or
// there are no radio buttons
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.checked) {
  return radioObj.value;
}
}
return \"\";
}
// set the radio button with the given value as being checked
// do nothing if there are no radio buttons
// if the given value does not exist, all the radio buttons
// are reset to unchecked

function setCheckedValue(radioObj, newValue) {
if(!radioObj)
return;
var radioLength = radioObj.length;
if(radioLength == undefined) {
radioObj.checked = (radioObj.value == newValue.toString());
return;
}
for(var i = 0; i < radioLength; i++) {
radioObj.checked = false;
if(radioObj.value == newValue.toString()) {
  radioObj.checked = true;
}
}
}
check函数,判断所有单选框是否有未选择的,如果有显示提示.