Here is the form, with a multiple list:
------------------
<form name="form1" method="post" action="doit.php3">
  <select name="opciok" size="2" multiple>
    <option value="1">aaaaa</option>
    <option value="2">bbbbb</option>
    <option value="3">ccccc</option>
  </select>
  <input type="submit" name="Submit" value="Submit">
</form>

doit.php3:
-----------------
<?
echo $opciok; /* output: 3*/
/* It would be nice to use it as an array, to reach all the selected option values.

And I don't want to use the GET method, to parse the Query String.

*/
?>