function floor(number)
{
  return Math.floor(number*Math.pow(10,2))/Math.pow(10,2);
}
function dosum(){
  var mi = calcform.interestrate.value / 1200;
  var base = 1;
  var mbase = base + mi;
  for(i = 0; i < calcform.term.value * 12; i++){
    base = base * mbase;
  }
  var totalpurchaseprice = (eval(calcform.purchaseprice.value) + eval(calcform.salestax.value) + eval(calcform.otherfees.value) + eval(calcform.warranty.value));

  var loanamountdesired = (totalpurchaseprice - eval(calcform.downpayment.value));

  var dasum = loanamountdesired * mi / ( 1 - (1/base));
  calcform.loantotal.value = loanamountdesired
  calcform.loantotalwithinterest.value = loanamountdesired + (loanamountdesired * mi) * (eval(calcform.term.value) * 12);
  calcform.monthlypayment.value = floor(dasum);
}