input text dinamiche

[badaze]

Prova questo.

<script>
// settato per la prova
riga = 2;
function moltiplica() {
 for(var k=1;k<riga+1;k++){ 
 var x = 1;
    for(var j=0;j<4;j++) { 
      var nome="id"+j+k;
   x = x * parseFloat(document.getElementById(nome).innerText);
    }
 var destino = "id5"+k;
 document.getElementById(destino).innerText = x;
 }
}
</script>
<table>
<tr>
 <td >C1</td><td>C2</td><td>C3</td><td>C4</td><td>C5</td><td>Totale</td>
</tr>
<tr>
 <td id="id01">1</td><td id="id11">2</td><td id="id21">3</td><td id="id31">4</td><td id="id41">5</td><td id="id51"></td>
</tr>
<tr>
 <td id="id02">10.1</td><td id="id12">20.2</td><td id="id22">30</td><td id="id32">40</td><td id="id42">50</td><td id="id52"></td>
</tr>
<table>
 <input type="button" id="c" value="Calcola" onclick="moltiplica()"/><br />