PHP & MYSQL & JAVASCRIPT Help

[lpxxfaintxx]

Hello,

I have 2 MySQL tables, 'Main Category', and 'Sub-Category.'

Basically, the Main Category is the main/parent category, and the Sub-Category is a child of the main. In Sub-Category, there's 3 fields, subid, maincatid, and name. What I want is 2 dynamic dropdown menus. The first one, makes a query and gets all the Main Categories AND all the rows. Then, another query is made. The new query gets all the Sub-Categories thats field, 'maincatid' is the chosen one from the first drop-down menu. The second drop-down menu is updated, grabbing all of the correct Sub-Categories. Sorry, I am a bad explainer. If you are confused on what I am saying, please contact me through either this thread, my AIM, or my MSN. (AIM: BAGFULLOFRiCE MSN: [e-mail])

Regards,

Help would be GREATLY appreciated.

P.S. This is what I have so far

<select name="category">
        <option value="Default">Choose A Category:</option>
        <?php $query = "SELECT * FROM category";
	$result = mysql_query ($query);
	while ($row = mysql_fetch_array
		($result, MYSQL_NUM)) {
echo "<option value='{$row[0]}'>{$row[0]}</option>";} ?>
      </select></label></td>
  </tr>
  <tr>
    <td align="right" valign="bottom">&nbsp;</td>
    <td><select name="subcategory">
        <option value="Default">Choose A Sub-Category:</option>
        <?php $query = "SELECT * FROM subcategory WHERE maincatid = 'AHHHH! Help!'";
	$result = mysql_query ($query);
	while ($row = mysql_fetch_array
		($result, MYSQL_NUM)) {
echo "<option value='{$row[0]}'>{$row[0]}</option>";} ?>
      </select>