function ins(form,ans) {
  form.Answer.value=ans
  }

function RfTscore(noItems, code) {
  if (document.forms[noItems].done.value=="0") {
     document.forms[noItems].done.value="1"
  }
  else {
     document.forms[noItems].message.value="Exercise cannot be resubmitted."
     document.forms[noItems].message2.value="  "
     return true
  }
  
  results = new Array ()
  var noCorrect = 0
  var codeString = code.value
  var key = "abcdefgxyz"
  var keylen = key.length
  var currForm

  for (var j = 0; j < noItems; j++){
     currForm=document.forms[j]
     if (currForm.Answer.value=="0") {
         var itemNo = j+1
         document.forms[noItems].done.value="0"
         document.forms[noItems].message.value="Please answer all items first."
         document.forms[noItems].message2.value="  "
         return true
     }
         
//     currForm.Result.value=currForm.Answer.value
     var answerInt = codeString.charCodeAt(j)
     var keyInt = key.charCodeAt(j%keylen)
     var answer = String.fromCharCode(answerInt ^ keyInt)         
     if (currForm.Answer.value==parseInt(answer))  {
            noCorrect++
	results[j] = 1
    }
     else {
            results[j] = 0
     }
  }

  if (noItems==noCorrect) {
       mess = "All answers are correct (score = 100%)."
      }
  else if (noCorrect == 0) {
         mess = "All answers are incorrect (score = 0%)."
      }
  else {
     var s = 100*noCorrect/noItems
     mess = "Score = "+s+"%."
     }

  document.forms[noItems].message.value = mess

  for (var j = 0; j < noItems; j++){
    currForm = document.forms[j]
    var ans = currForm.Answer.value
    var c
    
    if (ans == "1") {
       c = "a"}
    else if (ans == "2") {
       c = "b"}
    else if (ans == "3") {
       c = "c"}
    else {
       c = "d"}
    
    var d = " is correct."
    if (results[j] == 0) {
       d = " is incorrect."
      }

    currForm.Result.value = "Answer "+c+d
  }

  return true

}