calc going wrong with loan script

[spike-spiegel]

There is this script that calculates a loan by dividing and raising taxes according to amount of installments.

But it is calculating wrong, if you divide 140 for 3, it will work just fine, but if you do it with 999, it wont give the correct result:

 

 

<script>
function calcula(parcela){
var valor= parseFloat(document.getElementById("avista").value);
var parcela= parseFloat(parcela);

document.getElementById("resultado").value = (valor+50)*parcela;

}
</script>

<font face="Verdana" size="2">
Digite aqui o valor do empréstimo:<br>




<!--  Formata dados -->
<script type="text/javascript"><!-- Original:  Mario Costa (mariocosta@openlink.com.br) -->
<!-- Bug fix:   John Kiernan  -->

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->

<!-- Begin
function currencyFormat(fld, milSep, decSep, e) {

	var isIE8 = false;
	if (window.ActiveXObject) { // IE
		// http://www.javascriptkit.com/javatutors/navigator.shtml
		if (/MSIE (\d+\.\d+);/.test(navigator.userAgent)){ //test for MSIE x.x;
			 var ieversion=new Number(RegExp.$1) // capture x.x portion and store as a number
			 if (ieversion>=
			 {
			 	isIE8 = true;
			 }
			 else if (ieversion>=7) 
			 {
			 }
			 else if (ieversion>=6)
			 {
			 }
			 else if (ieversion>=5)
			 {
			 }
		}
	}

	var isChrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;

if (isIE8 /*|| isChrome*/)
{
}
else
{
	var sep = 0;
	var key = '';
	var i = j = 0;
	var len = len2 = 0;
	var strCheck = '0123456789';
	var aux = aux2 = '';
	var whichCode = (window.Event) ? e.which : e.keyCode;
	if (whichCode == 13) return true;  // Enter
	if (whichCode ==  return true;  // Delete (Bug fixed)
	key = String.fromCharCode(whichCode);  // Get key value from key code
	if (strCheck.indexOf(key) == -1) return false;  // Not a valid key
	len = fld.value.length;
	for(i = 0; i < len; i++)
	if ((fld.value.charAt(i) != '0') && (fld.value.charAt(i) != decSep)) break;
	aux = '';
	for(; i < len; i++)
	if (strCheck.indexOf(fld.value.charAt(i))!=-1) aux += fld.value.charAt(i);
	aux += key;
	len = aux.length;
	if (len == 0) fld.value = '';
	if (len == 1) fld.value = '0'+ decSep + '0' + aux;
	if (len == 2) fld.value = '0'+ decSep + aux;
	if (len > 2) {
	aux2 = '';
	for (j = 0, i = len - 3; i >= 0; i--) {
	if (j == 3) {
	aux2 += milSep;
	j = 0;
	}
	aux2 += aux.charAt(i);
	j++;
	}
	fld.value = '';
	len2 = aux2.length;
	for (i = len2 - 1; i >= 0; i--)
	fld.value += aux2.charAt(i);
	fld.value += decSep + aux.substr(len - 2, len);
	}
	return false;
}
}
//  End -->
</script>
<!-- Fim da formatação de dados -->





<input type="text" id="avista"> <!-- onkeypress="return(currencyFormat(this,'',',',event))"> -->

<br>
<select name="parcelas" size="1" onchange="calcula(this.value)">
<option value="">Parcelas</option>
<option value="0.3128">2x com juros de % ao mês.</option>
<option value="0.2528">3x</option>
<option value="0.1575">4x</option>
<option value="0.1102">5x</option>
<option value="0.1039">6x</option>
<option value="0.1039">7x</option>
<option value="0.1039">8x</option>
<option value="0.1039">9x</option>
<option value="0.1039">10x</option>
<option value="0.1039">11x</option>
<option value="0.1039">12x</option>
</select>
<br>
<hr size="1" color="gray">
Resultado:
<input type="text" id="resultado" readonly>



</BODY>
</HTML>

 

 

 

Ps: I think it's a problem with

document.getElementById("resultado").value = (valor+50)*parcela;

 

the 50 part

[Andy-H]

CBA to read all that but

function calcula(parcela){
   var valor= parseFloat(document.getElementById("avista").value);
   var parcela= parseFloat(parcela);
   document.getElementById("resultado").value = (valor+50)*parcela;
}

 

function calcula(parcela){
   var valor= parseFloat(document.getElementById("avista").value);
   parcela  = parseFloat(parcela);
   document.getElementById("resultado").value = (valor+50)*parcela;
}

 

 

parcela is a parameter, the var is probably messing it up...

[spike-spiegel]

Parcela means installment in english, the taxes are multiplied by avista (one time price) and divided by installments I guess. 

 

 

what I know is that it calcs 14 per 3 correctly, 140 per 3 correctly, but something like 999 / 3 won't calc correctly...