Ops scusami, non avevo capito bene. Ti passo tutto lo script, completo, in realtà l'addizione è solo parte di uno script che segue anche alcune divisioni partendo da valori inseriti all'interno dello stesso campo.
codice:
<!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=iso-8859-1" />
<title>Documento senza titolo</title>
<script language = "Javascript">
function taLimit() {
var taObj=event.srcElement;
if (taObj.value.length==taObj.maxLength*1) return false;
}
function taCount(visCnt) {
var taObj=event.srcElement;
if (taObj.value.length>taObj.maxLength*1) taObj.value=taObj.value.substring(0,taObj.maxLength*1);
if (visCnt) visCnt.innerText=taObj.maxLength-taObj.value.length;
}
function division1()
{
var div1, div2, resultwe;
div1 = parseFloat(document.form1.divis1.value);
div2 = parseFloat(document.form1.divisore.value);
resultwe = div1 / div2;
document.form1.txtNumber1.value = resultwe;
}
function division2()
{
var div3, div4, resultwr;
div3 = parseFloat(document.form1.divis2.value);
div4 = parseFloat(document.form1.divisore.value);
resultwr = div3 / div4;
document.form1.txtNumber2.value = resultwr;
}
function division3()
{
var div5, div6, resultqw;
div3 = parseFloat(document.form1.divis3.value);
div4 = parseFloat(document.form1.divisore.value);
resultqw = div3 / div4;
document.form1.txtNumber3.value = resultqw;
}
function addition()
{
var number1, number2, number3, result;
number1 = (isNaN(txtNumber1))? 0 : parseFloat(document.form1.txtNumber1.value);
number2 = (isNaN(txtNumber2))? 0 : parseFloat(document.form1.txtNumber2.value);
number3 = (isNaN(txtNumber3))? 0 : parseFloat(document.form1.txtNumber3.value);
result =(number1 + number2 + number3);
document.form1.txtResult.value=result;
}
function addition2()
{
var number4, number5, number6, resultz;
number4 = (isNaN(divis1))? 0 : parseFloat(document.form1.divis1.value);
number5 = (isNaN(divis2))? 0 : parseFloat(document.form1.divis2.value);
number6 = (isNaN(divis3))? 0 : parseFloat(document.form1.divis3.value);
resultz =(number4 + number5 + number6);
document.form1.txtResultz.value=resultz;
}
</script>
</head>
<body>
<form id="form1" name="form1" method="post" action="">
<table width="300" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="100" height="30"></td>
<td width="100" height="30"><div align="center">Divisore</div></td>
<td width="100" height="30"><div align="center">
<input name="divisore" type="text" id="divisore" size="8" />
</div></td>
</tr>
<tr>
<td width="100" height="30"><div align="center">1° Numero </div></td>
<td width="100" height="30">
<div align="center">
<input name="divis1" type="text" id="divis1" onkeyup="division1();addition2()" size="8" />
</div></td>
<td width="100" height="30"><div align="center">
<input name="txtNumber1" type="text" id="txtNumber1" onchange="addition()" size="8" />
</div></td>
</tr>
<tr>
<td width="100" height="30"><div align="center">2° Numero </div></td>
<td width="100" height="30">
<div align="center">
<input name="divis2" type="text" id="divis2" onkeyup="division2();addition2()" size="8" />
</div></td>
<td width="100" height="30"><div align="center">
<input name="txtNumber2" type="text" id="txtNumber2" onchange="addition()" size="8" />
</div></td>
</tr>
<tr>
<td width="100" height="30"><div align="center">3° Numero </div></td>
<td width="100" height="30">
<div align="center">
<input name="divis3" type="text" id="divis3" onkeyup="division3();addition2()" size="8" />
</div></td>
<td width="100" height="30"><div align="center">
<input name="txtNumber3" type="text" id="txtNumber3" onchange="addition()" size="8" />
</div></td>
</tr>
<tr>
<td width="100" height="30"><div align="center">Risultati</div></td>
<td width="100" height="30">
<div align="center">
<input name="txtResultz" type="text" id="txtResultz" size="8" />
</div></td>
<td width="100" height="30"><div align="center">
<input name="txtResult" type="text" id="txtResult" size="8" />
</div></td>
</tr>
<tr>
<td width="100" height="30"></td>
<td width="100" height="30"><div align="center"></div></td>
<td width="100" height="30"><div align="center"></div></td>
</tr>
</table>
</form>
</body>
</html>