title: how find radio button value
body: <p>i have a four radio buttons in a row.
  so i have 10 rows in a table. all radio buttons in a row having same id.
  in one time, only one radio button in a row can be selected.
  some radio buttons are checked and some non checked.
  i want to put a validation when submit the form. when i submit the form if all radio button is non selected in a row then a msg box can be appear.
  i have found the radio button id but i am not able to get their value, either true or false.
  it show me in a alert box: <code>radiobutton Value is: undefined</code></p>
  
  <p>here is the method:</p>
  
  <pre><code>function showValue() {
  var  radioID="radiobutton";
  var radiobuttonName;
  var radiobuttonValue;
     for (var i=0;i&lt;10;i++) {
    radiobuttonName=radioID+i;
    alert("radiobutton Name is:"+radiobuttonName);
    if (radiobuttonName.checked)
    {
        radiobuttonValue=radiobuttonName.value
    }
   alert("radiobutton Value is:"+radiobuttonValue);
      }
  }
  </code></pre>
  
  <blockquote>
    <p>Edit:</p>
  </blockquote>
  
  <p>i have four radio button in a row.
  name and id is same of all four button in a row.
  suppose, name and id for all buttons in first row is radiobutton0. for second row it is radiobutton1, for third row it is radiobutton2. thus i have 10 rows in a table.
  my aim is  when i submit the page, one button must be checked in a row else it show a msg box that please fill the corresponding radio button. .
  i want to get the value of radio button either true or false.</p>
  
  <p>i run the following code:<code>function get_radio_value()
  {
      var  radioID="radiobutton";
  var radiobuttonName;
  var radiobuttonValue;
     for (var i=0;i&lt;10;i++) {
    radiobuttonName=radioID+i;
    alert("radiobutton Name is:"+:"+radiobuttonName);
  }
  }
  </code>
   this method execute the loop and display all radiobutton Names.
  How i find radiobuttonValue which is either true or false.</p>