Amigos ya lo logre.
Gracias, lo hice asi:
<SCRIPT LANGUAGE="JavaScript">
function formCheck()
{
if (document.theform.nombre.value == "")
{
alert("Please Fill the description Box.");
return false;
}
if (document.theform.fichero.value == "")
{
alert("Please Select a file to send.");
return false;
}
}
// End -->
</script>
<link rel="stylesheet" href="../css/addNewForm2.css" type="text/css">
<title>Formulario de envío de ficheros</title>
</head>
<body>
<%
Call DoPageHeader
%>
<h3 align="center">Upload the image.</h3>
<p>&nbsp;</p>
<form action="uptest.asp" method="post" enctype="multipart/form-data" NAME = "theform" onSubmit="return formCheck()">>
<table width="75%" border="0">
<tr>
<td>Comment about the Image</td>
<td>
<textarea name="nombre" cols="50" rows="5"></textarea>
</td>
</tr>
<tr>
<td>Select the image</td>
<td>
<input type="file" name="fichero" size="20">
</td>
</tr>
<tr>
<td>&nbsp;</td>
<td>
<input type="submit" name="submit" > ;)
Pura Vida!