// Radio Button Validation
// copyright Stephen Chapman, 15th Nov 2004,14th Sep 2005
// from http://javascript.about.com/library/blradio1.htm
// you may copy this function but please keep the copyright notice with it
// example :
// var btn = valButton(form.group1);
// if (btn == null) alert('No radio button selected');
// else alert('Button value ' + btn + ' selected'); 

function valButton(btn) {
    var cnt = -1;
    for (var i=btn.length-1; i > -1; i--) {
        if (btn[i].checked) {cnt = i; i = -1;}
    }
    if (cnt > -1) return btn[cnt].value;
    else return null;
}

// the 4 following RadioGroup related functions come from http://www.faqts.com/knowledge_base/view.phtml/aid/1763
function preserveRadioGroup (evt) {
  this.checked = this.storedChecked;
  var rgb = this.form[this.name];
  if (!rgb.length && rgb.storedChecked)
    rgb.checked = true;
  else 
    for (var b = 0; b < rgb.length; b++)
      rgb[b].checked = rgb[b].storedChecked ? true : false;
}
function disableRadioGroup (radioGroup) {
  if (!radioGroup.disabled) {
    radioGroup.disabled = true;
    if (document.all || document.getElementById) {
      if (!radioGroup.length)
        radioGroup.disabled = true;
      else
        for (var b = 0; b < radioGroup.length; b++)
          radioGroup[b].disabled = true;
     }
    else {
      if (!radioGroup.length) {
        radioGroup.storedChecked = radioGroup.checked;
        radioGroup.oldOnClick = radioGroup.onclick;
        radioGroup.onclick = preserveRadioGroup;
      }
      else
        for (var b = 0; b < radioGroup.length; b++) {
          radioGroup[b].storedChecked = radioGroup[b].checked;
          radioGroup[b].oldOnClick = radioGroup[b].onclick;
          radioGroup[b].onclick = preserveRadioGroup;
        }
    }
  }
}
function enableRadioGroup (radioGroup) {
  if (radioGroup.disabled) {
    radioGroup.disabled = false;
    if (document.all || document.getElementById) {
      if (!radioGroup.length)
        radioGroup.disabled = false;
      else
        for (var b = 0; b < radioGroup.length; b++)
          radioGroup[b].disabled = false;
     }
    else {
      if (!radioGroup.length) {
        radioGroup.onclick = radioGroup.oldOnClick;
      }
      else
        for (var b = 0; b < radioGroup.length; b++) {
          radioGroup[b].onclick = radioGroup[b].oldOnClick;
        }
    }
  }
}