// JavaScript Document
<!-- Begin
function startCalc(){
  interval = setInterval("calc()",1);
}
function RoundTo2dp(X) { return Math.round(X*100)/100 }
function calc(){
  LPGpercent = 1.05
  one = document.autoSumForm.firstBox.value;
  two = document.autoSumForm.secondBox.value;
  three = document.autoSumForm.thirdBox.value;
  four = document.autoSumForm.fourthBox.value;
  five = document.autoSumForm.fifthBox.value;
  six = document.autoSumForm.sixthBox.value;

  document.autoSumForm.fifthBox.value = RoundTo2dp(((two * 1) / (one * 1)) * (three *1));
  document.autoSumForm.sixthBox.value = RoundTo2dp((((two * 1) / (one * 1)) * (four *1) * LPGpercent));
  document.autoSumForm.seventhBox.value = RoundTo2dp((five * 1) - (six * 1));

}
function stopCalc(){
  clearInterval(interval);
}
//  End -->