Cod: Selectaţi tot

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Calculare Valoare + TVA in Java Script</title>
 </head>
 
 <body>
    <script type="text/javascript" language="javascript">
    <!--
       // functia pentru calculare valoare si tva
       // Autor: Birkoff - www.farsoft.far-php.ro
       // Data: 06.08.2009
       // Rev: 1
       function calculare_valoare(camp, valoare) {
 
          // preluare valori existente
          var buc = document.getElementById('buc').value;
          var pret = document.getElementById('pret').value;
          var tva = 0.19; // 19 %
          // schimbare virgula cu punct (daca exita)
          buc = buc.replace(/,/gi, '.');
          pret = pret.replace(/,/gi, '.');
          valoare = valoare.replace(/,/gi, '.');
          // calculare valoare
          if (camp == 'buc') {
              var val = valoare * pret;
          }
          if (camp == 'pret') {
              var val = valoare * buc;
          }
          // calculare tva
          var suma_tva = val + (val * tva);
          var val_tva = suma_tva - val;
          // afisare valori
          document.getElementById('val').value = val.toFixed(2);
          document.getElementById('tva').value = val_tva.toFixed(2);
          // teste - afisam valorile in div
          document.getElementById('scrie').innerHTML = buc + ' + ' + pret;
       }
 
    -->
    </script>
    <div id="scrie">
    </div>
 <form action="" method="post" name="test">
   <label for="buc">Bucati:</label>
   <input name="buc" type="text" id="buc" value="0" onchange="calculare_valoare(this.id, this.value)" />
  x
  <label for="pret">Pret:</label>
  <input name="pret" type="text" id="pret" value="0" onchange="calculare_valoare(this.id, this.value)" />
  =
  <label for="val">Valoare:</label>
  <input name="val" type="text" id="val" value="0" readonly="readonly" />
  <label for="tva">(tva 19%)</label>
  <input name="tva" type="text" id="tva" value="0" readonly="readonly" />
 </form>
 </body>
 </html>