one to many checkboxes update, what am i missing??

[john6767]

i have a page that has a product, and this product has one to many sizes that the user can add or remove by using checkboxes.

i have checkboxes that are appearing correctly and are either checked or unchecked, i am having troubles getting the changes to these checkboxes updated into the database,

here is my checkbox code so you can see the name..

<input name="size_id[]" type="checkbox" id="size_id[]" value="">

here is my update code..

if (isset($_POST['size_id'])){
		foreach ($_POST['size_id'] as $size_id) {
		echo "checkbox value checked: " .$size_id ."<BR>";

  //Delete from sizesball (the join table) only those that have been deselected

  if ($size_id <> "") {
   $updateSQL2 = sprintf("DELETE FROM balls_sizes WHERE size_id not in(%s) and ball_id=%s",
                       $size_id,
                       GetSQLValueString($_POST['ball_id'], "int"));

  mysql_select_db($database_cnnTest, $cnnTest);
  $Result2 = mysql_query($updateSQL2, $cnnTest) or die(mysql_error());
  }

  //Now insert any newly selected sizes into sizesball

}
foreach ($_POST['size_id'] as $size_id) {

//First check to see if that size is already in the table sizesball

mysql_select_db($database_cnnTest, $cnnTest);
$query_rssizesballs = sprintf("SELECT size_id, ball_id FROM balls_sizes where ball_id =%s and size_id = %s",
                        GetSQLValueString($_POST['ball_id'], "int"), $size_id);

$rssizesballs = mysql_query($query_rssizesballs, $cnnTest) or die(mysql_error());
$row_rssizesballs = mysql_fetch_assoc($rssizesballs);
$totalRows_rssizesballs = mysql_num_rows($rssizesballs);

//If the recordset is empty, we can insert a new record

	if($totalRows_rssizesballs == 0) {
	  $updateSQL3 = sprintf("INSERT INTO balls_sizes (ball_id,size_id) VALUES (%s,%s)",   
							GetSQLValueString($_POST['ball_id'], "int"), $size_id);
	  $Result3 = mysql_query($updateSQL3, $cnnTest) or die(mysql_error());
	  }
  }
}