Obliczanie cenny netto i brutto Opcje

[wozniak]

Witam, mam skrypt ktory ma obliczac cene netto lub brutto zalezy która sie wpisze ale cos mi nie działa:( Kod:

[HTML] pobierz, plaintext 
<script language="javascript"><!--
var tax_rates = new Array();
tax_rates["1"] = 0;
tax_rates["2"] = 3;
tax_rates["3"] = 6;
tax_rates["4"] = 7;
tax_rates["5"] = 21;
tax_rates["6"] = 22;
function doRound(x, places) {
  return Math.round(x * Math.pow(10, places)) / Math.pow(10, places);
}
 
function getTaxRate() {
  var selected_value = document.forms["new_product"].prod_z_vat.selectedIndex;
  var parameterVal = document.forms["new_product"].prod_z_vat[selected_value].value;
 
  if ( (parameterVal > 0) && (tax_rates[parameterVal] > 0) ) {
    return tax_rates[parameterVal];
  } else {
    return 0;
  }
}
 
function updateGross() {
  var taxRate = getTaxRate();
  var grossValue = document.forms["new_product"].prod_z_netto.value;
 
  if (taxRate > 0) {
    grossValue = grossValue * ((taxRate / 100) + 1);
  }
 
  document.forms["new_product"].prod_z_brutto .value = doRound(grossValue, 4);
}
 
function updateNet() {
  var taxRate = getTaxRate();
  var netValue = document.forms["new_product"].prod_z_brutto.value;
 
  if (taxRate > 0) {
    netValue = netValue / ((taxRate / 100) + 1);
  }
 
  document.forms["new_product"].prod_z_netto.value = doRound(netValue, 4);
}
//--></script>
 
 
<form method="POST" action="--WEBBOT-SELF--" enctype="multipart/form-data">
<table border="0" cellpadding="0" cellspacing="0" width="567" height="605">
	<tr>
		<td height="38" width="567" colspan="2">&nbsp;</td>
	</tr>
	<tr>
		<td height="21" width="132">Nazwa Produktu:&nbsp;
					</td>
		<td height="21" width="435">
		<input type="text" name="T1" size="20"></td>
	</tr>
	<tr>
		<td height="23" width="132">Producent:</td>
		<td height="23" width="435"><select size="1" name="D1"></select></td>
	</tr>
	<tr>
		<td height="19" width="132">Jezyk:</td>
		<td height="19" width="435"><select size="1" name="D4"></select></td>
	</tr>
	<tr>
		<td height="21" width="132">Kod:</td>
		<td height="21" width="435"><input type="text" name="T2" size="20"></td>
	</tr>
	<tr>
		<td height="21" width="132">Magazyn:</td>
		<td height="21" width="435"><select size="1" name="D2"></select></td>
	</tr>
	<tr>
		<td height="21" width="132">Ilosc</td>
		<td height="21" width="435"><input type="text" name="T7" size="11"></td>
	</tr>
	<tr>
		<td height="21" width="132" bgcolor="#EBEBFF">
		<p align="right">Klasa podatku:</td>
		<td height="21" width="435" bgcolor="#EBEBFF">
		<select name="prod_z_vat" onchange="updateGross()">
		<option value="1" selected>Vat 0</option>
		<option value="2">Vat 3</option>
		<option value="3">Vat 6</option>
		<option value="4">Vat 7</option>
		<option value="5">Vat 21</option>
		<option value="6">Vat 22</option>
		</select>%</td>
	</tr>
	<tr>
		<td height="21" width="132" bgcolor="#EBEBFF">
		<p align="right">Zakup: Cena netto:</td>
		<td height="21" width="435" bgcolor="#EBEBFF">
		<input onkeyup="updateGross()" name="prod_z_netto" size="11"> x</td>
	</tr>
	<tr>
		<td height="7" width="132" bgcolor="#EBEBFF">
		<p align="right">brutto:</td>
		<td height="7" width="435" bgcolor="#EBEBFF">
		<input onkeyup="updateNet()" name="prod_z_brutto" size="11"> x</td>
	</tr>
	<tr>
		<td height="21" width="132" bgcolor="#EBEBFF">
		<p align="right">Klasa podatku:</td>
		<td height="21" width="435" bgcolor="#EBEBFF">
		<select size="1" name="D5">
		<option>0</option>
		<option>3</option>
		<option>6</option>
		<option>7</option>
		<option>21</option>
		<option>22</option>
		</select>%</td>
	</tr>
	<tr>
		<td height="21" width="132" bgcolor="#EBEBFF">
		<p align="right">Sprzedaz: Cena netto:</td>
		<td height="21" width="435" bgcolor="#EBEBFF">
		<input type="text" name="T5" size="11"> x</td>
	</tr>
	<tr>
		<td height="24" width="132" bgcolor="#EBEBFF">
		<p align="right">brutto:</td>
		<td height="24" width="435" bgcolor="#EBEBFF">
		<input type="text" name="T6" size="11"> x</td>
	</tr>
	<tr>
		<td height="19" width="132" bgcolor="#EBEBFF">
		<p align="right">Max upust w %: </td>
		<td height="19" width="435" bgcolor="#EBEBFF">
		<input type="text" name="T9" size="11">%</td>
	</tr>
	<tr>
		<td height="66" width="132">Opis:</td>
		<td height="66" width="435">&nbsp;</td>
	</tr>
	<tr>
		<td height="9" width="567" colspan="2">
		<textarea rows="11" name="S1" cols="72"></textarea></td>
	</tr>
	<tr>
		<td height="14" width="132">
		<p align="center"></td>
		<td height="14" width="435"></td>
	</tr>
	<tr>
		<td height="6" width="132">Zdjecie 1</td>
		<td height="6" width="435"><input type="file" name="F1" size="20"></td>
	</tr>
	<tr>
		<td height="13" width="132">Zdjecie 2</td>
		<td height="13" width="435"><input type="file" name="F2" size="20"></td>
	</tr>
	<tr>
		<td height="7" width="132">Zdjecie 3</td>
		<td height="7" width="435"><input type="file" name="F3" size="20"></td>
	</tr>
	<tr>
		<td height="19" width="132">Waga produktu</td>
		<td height="19" width="435">
		<input type="text" name="T8" size="8">kg</td>
	</tr>
	<tr>
		<td height="25" width="567" colspan="2">
		<p align="center"><input type="submit" value="Dodaj" name="B1"></td>
	</tr><script language="javascript"><!--
updateGross();
//--></SCRIPT>
</table>
<p>&nbsp;</p>
</form>
[HTML] pobierz, plaintext 

[wozniak]

A jak chce dodac jeszcze to przeliczanie do sprzedazy to musze jeszcze raz skopiowac funkcje i pozmieniac tam nazwy itp? czy mozna to jakosc łatwiej rozwiazac?