function sapNextQues(quesId, ansId) {
  var curId = 'q_' + quesId + '_' + ansId;
  var turnOnQues = document.getElementById(curId);

  getPrevOpen(curId);

  turnOnQues.className = turnOnQues.className.replace('displayNone', 'displayBlock');
}

function getPrevOpen(curId) {
  var oq = getElementsByClassName('question displayBlock', 'div')
  var op = getElementsByClassName('process displayBlock', 'div');
  var findOpenQues = oq.concat(op);

  for (var i = 0, j = findOpenQues.length; i < j; i++) {
    var openId = findOpenQues[i].getAttribute('id');
    curIdSize = countUnderscore(curId);
    openIdSize = countUnderscore(openId);

    if ((curIdSize == openIdSize) || (curIdSize < openIdSize)) {
      var openQues = document.getElementById(openId);

      clearRadio(openId);

      openQues.className = openQues.className.replace('displayBlock', 'displayNone');
    }
  }
}

function countUnderscore(strToSplit) {
  var charToCount = '_';
  var counter = 0;
  var charArray = strToSplit.split('');

  for (i = 0; i < charArray.length; i++) {
    if (charArray[i] == charToCount) {
      counter++
    }
  }
  return counter;
}

function clearRadio(openDivId) {
  var startPt = openDivId.indexOf('_') + 1;
  var radioName = 'ques_' + openDivId.substr(startPt, openDivId.length);
  var r = document.getElementsByName(radioName);

  for (i = 0; i < r.length; i++) {
    r[i].checked = false;
  }
}