function getValue(obj) {
    document.forms[0].rate.value = obj.options[obj.selectedIndex].value;


  }




function showpay() {
  var dd = document.calc.months.selectedIndex;
  var ss = document.calc.months[dd].text;
 

 if ((document.calc.loan.value == null || document.calc.loan.value.length == 0) ||
     (document.calc.months.value == null || document.calc.months.value.length == 0)
||
     (document.calc.rate.value == null || document.calc.rate.value.length == 0))
 { document.calc.pay.value = "Incomplete data";
 }
 else
 {
 var dd = document.calc.months.selectedIndex;
 var term = document.calc.months[dd].text;
 var princ = document.calc.loan.value;
 var intr   = document.calc.rate.value / 100;
 var jumintr = princ * intr * term;
 var bulan = term * 12; 
 var byrn = ( jumintr*1 + princ*1 ) / bulan;
 var jum = Math.round(byrn*100)/100;
 document.calc.pay.value = jum  ;


 }

// payment = principle * monthly interest/(1 - (1/(1+MonthlyInterest)*Months))

}