//<!--
 function select_item(name, value) {
        this.name = name;
        this.value = value;
    }
    function get_selection(select_object) {
        contents = new select_item();
        for(var i=0;i<select_object.options.length;i++)
           if(select_object.options[i].selected == true) {
                contents.name = select_object.options[i].text;
                contents.value = select_object.options[i].value;
            }
        return contents;
    }
// Function to calculate Periodic Payments.
function pmt(formfield)
{
   
   var fv = formfield.balloon.value;
   //var nper = get_selection(formfield.term);
   //nper = nper.value;
   var nper_item = document.formfield.term.selectedIndex;
   var nper = document.formfield.term.options[nper_item].value;
   var rate_item = document.formfield.rate.selectedIndex;
   var rate = document.formfield.rate.options[rate_item].value;
   var pv = formfield.amount.value;
   var balper = formfield.balper.value;
	var baserate="1";
	var taxrate="1";
	var taxes ="0";

   //make sure the amount financed is not negative.
	if (pv < 0) {
		alert("The value of the amount financed (car price) must not be less than $0");
	 return false;}
   pv = pv.replace("$","");
   pv = pv.replace(",","");
   fv = fv.replace("$","");
   fv = fv.replace(",","");
   balper = balper.replace("$","");
   balper = balper.replace(",","");
   balper = balper.replace("%","");

if (formfield.taxes.checked)
{
 	taxrate="1.13";	
	taxes=pv*.13;
}else
{
	taxes="0";
	taxrate="1";
}


   formfield.amount.value = pv;
   //used by program
   pv = -(pv*taxrate);
   



   //make sure the balper field is only b/w 0 and 100 and no negatives.
   if ((balper < 0) || (balper > 100)) {
		alert("The value for the percentage must be between 0 and 100 % ");
	 return false;}

    //make sure that all money is positive not negative	 
	if (fv < 0) {
		alert("The value for the down payment must not be less than $0");
	 return false;}

   //make sure that all money is positive not negative	 
	if (fv > -pv) {
		alert("The value for the down payment must not be more than the vehicle.");
	 return false;}
    
   if ((fv == 0) || (fv == "")) {
	  fv = -(pv*balper/100);
   }
   fv = parseFloat(fv);
   nper = parseFloat(nper);
   pv = parseFloat(pv);
   rate = parseFloat(rate);

   rate = eval((rate)/(12 * 100));
   if ( rate == 0 )    // Interest rate is 0
   {
       pmt_value = - (fv + pv)/nper;
   }
   else 
   {
       x = Math.pow(1 + rate,nper);
                   pmt_value = -((rate * ( x *(fv + pv)))/(-1 + x));
   }
   pmt_value = conv_number(pmt_value,2);		
   formfield.repayment.value = pmt_value;
	taxes=conv_number(taxes,2);
	formfield.taxesv.value= taxes;
}

function conv_number(expr, decplaces) 
{       // This function is from David Goodman's Javascript Bible.	
     var str = "" + Math.round(eval(expr) * Math.pow(10,decplaces));
     while (str.length <= decplaces) {
           str = "0" + str;
     }
     var decpoint = str.length - decplaces;
     return (str.substring(0,decpoint) + "." + str.substring(decpoint,str.length));
}
// -->