Ups,
so habs. Thread nicht angucken. Augenkrebsgefahr........
funzen tut es so:
<html>
<head>
<title>
Checkbox
</title>
<script type="text/javascript">
function show(fieldname)
{
alert(fieldname);
if(document.formular.boxone.checked)
{
document.getElementById(fieldname).style.visibility = "visible";
}
else
document.getElementById(fieldname).style.visibility = "hidden";
}
</script>
</head>
<body>
<form name="formular" action="">
<table border="1">
<tr>
<td>
<input type="checkbox" name="boxone" onClick="show('fieldone');">Click me
</td>
<td>
<input type="text" name="fieldone" style="visibility:hidden" value="Ihre Eingabe">
</td>
</tr>
</table>
</form>
</body>
</html>