function doMath(theForm) {


     var rate = document.getElementById("rate").value;
     var term = document.getElementById("term").value;
     var loan = document.getElementById("loan").value;

     if (document.getElementById("down_payment").value.length <= 0) {
           document.getElementById("down_payment").value = "0.00";
     }
     else {
           if
(isNaN(parseFloat(document.getElementById("down_payment").value))) {
                 document.getElementById("down_payment").value = "0.00";
           }
           else
                 if
(parseFloat(document.getElementById("down_payment").value) <= 0)
                       document.getElementById("down_payment").value = "0.00";
     }

     if ( parseFloat(document.getElementById("down_payment").value) > parseFloat(document.getElementById("loan").value) ) {
           document.getElementById("down_payment").value = "0.00";
     }
     var loan = loan - document.getElementById("down_payment").value;

     var numerator, denominator, periods, interestRate = 0;
     var i = rate;
     if (i > 1.0) {
           i = i * 0.01;
     }
     else {
     rate = 100 * rate;
   }

   interestRate = i / 12;

   periods = term * 12;
   numerator = loan * interestRate * Math.pow(1 + interestRate, periods);
   denominator = Math.pow(1 + interestRate, periods) - 1;
   document.getElementById("estPay").value=fixFloatFormat(numerator / denominator);

//    theForm.monthly.value = numerator / denominator;
//    fixFloatFormat (form.monthly);
     return true;
} //end calcMonthlyPay

function fixFloatFormat(input) {
     if ((input== 0) && (input.length == null)) {
           input= "0.00";
     }

     var temp = eval(input) + 0.005
     var cents = "" + (100 + Math.floor((temp - Math.floor(temp)) * 100));
     var dollars = "" + Math.floor(temp);

     return (dollars + "." + cents.substring(1,3));
}