function clear_Click(){
  document.analyzer.loan.value = "";
  document.analyzer.downp.value="";
  document.analyzer.term.value = "";
  document.analyzer.rate.value = "";
  document.analyzer.thedown.value="";
  document.analyzer.payment.value = "";
  
  
}

function calculate_Click(){
  var t1=0.0;
  var t=0.0;
  var i=0.0;
  var l=0.0;
  var x=0.0;
  var b=0.0;
  var t2=0.0;
  var im=0.0;
  var d=0.0;
  var n=0.0
  var p=0.0;
  var ia=0.0;
  var ip=0.0;
  var pp=0.0;
  var xpt=0.0;
  var dn=0.0;
  l = document.analyzer.loan.value;
  if (l=="") {
   alert ("A loan amount must be entered.");
   document.analyzer.loan.focus()
  }

  t = document.analyzer.term.value;
  if (t=="") {
   alert ("The loan's term in years must be entered.");
   document.analyzer.term.focus()
  }
  i = document.analyzer.rate.value;
  if (i=="") {
   alert ("The interest rate must be entered.");
   document.analyzer.rate.focus()
  }
  
  dn = document.analyzer.downp.value;
  if (dn=="") {
      dn = 0
  }

  if (dn > 0) {
     dn = dn/100;
     dn = l*dn;
  }
  document.analyzer.thedown.value = dn;
  b = l-dn;
  i = i/100;
  im = i/12;
  m = t*12;
  t2 = 1+im;
  t1 = Math.pow(t2, m);
  n = im*t1;
  d = t1-1;
  p = b*(n/d);
  t1 = p*100;
  t1 = Math.round(t1);
  p = t1/100;

  document.analyzer.payment.value = p;

  

 

  x = x*100;
  x = Math.round(x);
  x = x/100;



if (x < 0){
   alert( "Extra payment must be a positive value")
} 

if (x > 0){

var j
j = 0;
ip = 0;
pp = 0;

l1 = m+1;

while (b > 0) {    
      ia = im*b;
      ip = ip+ia;
      pp = p-ia;
      b = b-pp;
      b = b-x;
      j = j+1;

  }}
  }