str_replace code?

[syrus.xl]

I got this code in my admin file, however I need to add a str_replace before the data is posted. The str_replace code I'm trying to add is below, but I'm having problems on where it would actually go.

PHP Code:

    if ($_POST['do'] == "do_add_playlist1"){

    print_cp_header("Add New MP3 To Playlist 1");

    // Update Database

    $db->query("insert into ".TABLE_PREFIX."mp3playlist values(

    '','" . addslashes($_POST['url_product']) . "','" . addslashes($_POST['url_product_stream']) . "','" . addslashes($_POST['url_product_buffer']) . "','" . addslashes($_POST['mp3name']) . "',''

    )");

    define('CP_REDIRECT', 'mp3player_admin.php?do=playlist1');

    print_stop_message('mp3player_mp3_added');

    } 


str_replace code I need to insert.

PHP Code:

$playlistselect = $_POST[playlistselect];

$c = count ($_POST['mp3name']); 
  
  if($mp3playersettings['approvemp3']==1){
  $approvemp3 = 0;
  }else if($mp3playersettings['approvemp3']==0){
  $approvemp3 = 1;
  }
  for ($i = 0; $i < $c; $i++ ) {
$mp3name = $_POST['mp3name'][$i]; 
$mp3url = $_POST['mp3url'][$i]; 
$stream = $_POST['stream'][$i];
$soundbuffer = $_POST['soundbuffer'][$i];
$mp3name = str_replace("&quot;", " ", $mp3name);
  $mp3name = str_replace("&amp;", " ", $mp3name);
  $mp3name = str_replace("gt;", " ", $mp3name);
  $mp3name = str_replace("'", "''", $mp3name);
  $mp3url = str_replace("'", "''", $mp3url);
  $mp3url = str_replace("&quot;", " ", $mp3url);
  $mp3url = str_replace("&amp;", " ", $mp3url);
  $mp3url = str_replace("gt;", " ", $mp3url);
  if($playlistselect == 1){
  if($mp3name == ""){ 


Any help would be much appreciated.