function floor(number)
{
  return Math.floor(number*Math.pow(10,2))/Math.pow(10,2);
}

function dosum(formname)
{
  var calcform = document.getElementById(formname);
  var mi = calcform.IR.value / 1200;
  var base = 1;
  var mbase = 1 + mi;
  var totloan = calcform.LA.value * (1 + (calcform.PT.value/100))
  for (i=0; i<calcform.YR.value * 12; i++)
  {
    base = base * mbase
  }
  calcform.PI.value = floor(totloan * mi / ( 1 - (1/base)))
  calcform.MT.value = floor(calcform.AT.value / 12)
  calcform.MI.value = floor(calcform.AI.value / 12)
  var dasum = totloan * mi / ( 1 - (1/base)) +
        calcform.AT.value / 12 +
        calcform.AI.value / 12;
  calcform.MP.value = floor(dasum);
}