function pmt(rate, per, nper, pv, fv)
{
   fv = parseFloat(fv);
   nper = parseFloat(nper);
   pv = parseFloat(pv);
   per = parseFloat(per);
   if (( per == 0 ) || ( nper == 0 )){ 
      alert("Why do you want to test me with zeros?");
      return(0);
   }
   rate = eval((rate)/(per * 100));
   if ( rate == 0 )    // Interest rate is 0
   {
       pmt_value = - (fv + pv)/nper;
   }
   else 
   {
       x = Math.pow(1 + rate,nper);
                   pmt_value = -((rate * (fv + x * pv))/(-1 + x));
   }
   pmt_value = conv_number(pmt_value,2);               
   return (pmt_value);
}

function conv_number(expr, decplaces) 
{      
     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));
}

function pmt(rate, per, nper, pv, fv)
{
   fv = parseFloat(fv);
   nper = parseFloat(nper);
   pv = parseFloat(- pv);
   per = parseFloat(per);
   if (( per == 0 ) || ( nper == 0 )){ 
      alert("Larger numbers work better than zeros...");
      return(0);
   }
   rate = eval((rate)/(per * 100));
   if ( rate == 0 )    // Interest rate is 0
   {
       pmt_value = - (fv + pv)/nper;
   }
   else 
   {
       x = Math.pow(1 + rate,nper);
                   pmt_value = -((rate * (fv + x * pv))/(-1 + x));
   }
   pmt_value = conv_number(pmt_value,2);               
   return (pmt_value);
}

function conv_number(expr, decplaces) 
{         
     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));
}