Topic awaiting preservation: PHP explode/implode (Page 1 of 1)

Maybe I just haven slept for awhile... But for the life of me, I can't figure out this problem...

I have a DB that stores quantity like this: "NM:10 M:31 G: 26"

I'm trying to make it so if someone submits something to the database thats already there, it adds to the quantity...

i.e.
$_POST['cond'] = M;
$_POST['qty'] = 10;

So "NM:10 M:31 G: 26" needs to become "NM:10 M:41 G: 26" and then update the mysql database.

I know its a whole explode/implode thing... But exploding it, adding the proper quantities, and then sending it back to the database seems to have me stupified...

$new = array();
foreach (explode($old) as $keyvalue)
{
 $temp = explode($keyvalue, ":");
 if ($temp[0] == $_POST['cond'])
     $temp[1] += int($_POST['qty']);
  $new[] = $temp[0] . ':' . $temp[1];
}
$new = implode($new, " ");

completly untested, and it's been years since i've written any php...

good luck,
so long,

->Tyberius Prime