php menu in loop

hello,

I am having a problem with a dropdown menu in php, the menu works fine, it displays everything as it should, but it will not pass down any values. the reason there is a $i next to it is because the number of menus must be the same as the counter in the loop, and each menu must have its own name obviously, so I opted for 'firstname$i' where the first menu would be seen as firstname0, 2nd being firstname1 etc....  the [] are there because tjhe user must be able to select multiple options from the menu.

the code section is:

<?

?>

<FORM method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<?


$i = 0;
while ( $i <= 5 ) {

//echo"Firstname: <input type='text' name='firstname$i'[] />";


echo"<select name= 'firstname[$i]'[] size=4 multiple>
  <option>Milk</option>
  <option>Coffee</option>
  <option>Tea</option>
</select>";

$i++;

}

?>

</Select>
<input type=Submit value=pass on>
</form>

<?


$var2 = $_POST['firstname0'];



print_r($var2);
?>

please can someone show me where it is that I am going wrong.

thanks, Gavin