function startCalc(){
  interval = setInterval("calc()",100);
}

function calc(){

var frm = document.costForm;

  lone = frm.livingNursing.value;
  ltwo = frm.livingPersonal.value; 
  lthree = frm.livingGifts.value; 
  lfour = frm.livingOther.value; 


  costa = (lone * 1) + (ltwo * 1) + (lthree * 1) + (lfour * 1);
frm.livingWeekly.value = new NumberFormat(costa).toFormatted();

  costb = (costa * 52);
frm.livingAnnual.value = new NumberFormat(costb).toFormatted();

  ione = frm.incomeState.value;
  itwo = frm.incomePrivate.value; 
  ithree = frm.incomeOther.value; 
  ifour = frm.incomeAa.value; 

  costc = (ione * 1) + (itwo * 1) + (ithree * 1) + (ifour * 1);
frm.incomeWeekly.value = new NumberFormat(costc).toFormatted();

  costd = (costc * 52);
frm.incomeAnnual.value = new NumberFormat(costd).toFormatted();

coste = (costd - costb);
frm.totalBalance.style.color = (coste < 0) ? 'red' : 'black';
frm.totalBalance.value = new NumberFormat(coste).toFormatted();
}

function stopCalc(){
  clearInterval(interval);
}