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

function dosum(form)
{
  

  var mi = form.IR.value / 1200;
  var base = 1;
  var mbase = 1 + mi;

  for (i=0; i<form.YR.value * 12; i++)
  {
    base = base * mbase
  }

  form.PI.value = floor(form.LA.value * mi / ( 1 - (1/base)))
  form.MT.value = floor(form.AT.value / 12)
  form.MI.value = floor(form.AI.value / 12)

  var dasum = form.LA.value * mi / ( 1 - (1/base)) +
	form.AT.value / 12 + 
	form.AI.value / 12;

  form.MP.value = floor(dasum);
}