David,

I altered it a bit and this still works for me:

<html>
<head>
<title></title>
</head>
<body>
<form>
<table>
<tr ID = "row1">
<td><input TYPE = "text"></td>
<td><select><option>One</option><option>Two</option></select></td>
</tr>
<tr>
<td><input TYPE = "button" VALUE = "Hide Row" ONCLICK = "row1.style.display = 'none';"></td>
<td><input TYPE = "button" VALUE = "Show Row" ONCLICK = "row1.style.display='';"></td>
</tr>
</table>
</form>
</body>
</html>

The select element hides and shows as it's supposed to. Instead of using "block" try using '' (two single ticks).

Chris