nanoT1m,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
</head>
<body>
<table id="test">
<tr>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td>3</td>
<td>4</td>
</tr>
</table>
<script>
function cell(form,i,j, val) {
var o = document.getElementById(form);
o.rows[i].cells[j].innerHTML = val;
}
cell("test",1,1,20) ;
</script>
</body>
</html>