Because you need to declare the select name being an array by adding [] to the end of the select name then you need to combine the elements of the array into one string before inserting it to the db you could use the code below. It will put them in separated by a comma
<?php
if ($submit) {
while (list($key, $val) = each ($HTTP_POST_VARS["OS"])) {
$string .= $val .", ";
}
$string = substr($string, 0, -2);
print $string;
}
?>
<head>
<title>Untitled</title>
</head>
<body>
<form action="<?php print $PHP_SELF; ?>" method="post">
<SELECT NAME="OS[]" SIZE='3' MULTIPLE>
<OPTION Value=''> </OPTION>
<OPTION Value='Win98'>Win98</OPTION>
<OPTION Value='Win2k'>Win2k</OPTION>
<OPTION Value='WinNT'>WinNT</OPTION>
</SELECT>
<input type="submit" name="submit" value="submit">
</form>
