Could you post your code? If you're using a select field set to multiple for example (where the user can select more than one option by holding down the ctrl key), you can just add [] after the name and call each of the values as an array.
<select name="slct[]" MULTIPLE>
<option value="Hello">Hello</option>
<option value="Goodbye">Goodbye</option>
<option value="more_text">More Text</option>
</select>
Then in your php file that processes the form, you could access those values using
$slct['0']
$slct['1']
$slct['2']
Is that what you were looking for?
Cgraz