GIFS help please

[spires]

Hi, can some tell what part of my code do i need to edit so i can upload GIFS as well as JPGS.

Thanks for all your help.

[code]
if(isset($_POST['thumb_submit'])) {

    $size = 100; // the thumbnail height
$width = 100; // size of width


    $filedir = 'thumb2_orig/'; // the directory for the original image
    $thumbdir = 'thumb2/'; // the directory for the thumbnail image
$largedir = 'large/'; // the directory for the large image
    $prefix = ''; // the prefix to be added to the original name

    $maxfile = '1000000'; // max file size
    $mode = octdec('0666'); // octdec -- Octal to decimal.
// The mode parameter consists of three octal number components specifying access restrictions for the owner,
// the user group in which the owner is in, and to everybody else in this order. e.g (666)
     
    $userfile_name = $_FILES['thumb']['name'];
    $userfile_tmp = $_FILES['thumb']['tmp_name'];
    $userfile_size = $_FILES['thumb']['size'];
    $userfile_type = $_FILES['thumb']['type'];
     
  // if you have a the image and name then carry on
    if (isset($_FILES['thumb']['name']))  {

$new_img_name = $id.$userfile_name;

// $prod_img = the image folder and the image and name
        $prod_img = $filedir.$new_img_name;

// $prod_img_thumb = the thumb folder, the prefix (if you want it) and the image and name
        $prod_img_thumb = $thumbdir.$prefix.$new_img_name;

//move_uploaded_file -- Moves an uploaded file to a new location.
//move the uploaded file to the image folder with a tempory name.
        move_uploaded_file($userfile_tmp, $prod_img);
// chmod -- Changes file mode,
// set the user interface for the image
        chmod ($prod_img, $mode);
        // getimagesize -- Get the size of an image
// find the size of the original image
        $sizes = getimagesize($prod_img);

        $aspect_ratio = $sizes[1]/$sizes[0];
// if its less than the size you want it, dont change
if ($sizes[1] <= $size) {
$new_width = $sizes[0];
$new_height = $sizes[1];
// else, change image size
}else{
$new_height = $size;
$new_width = $width;
  //  $new_width = abs($new_height/$aspect_ratio);
// this code will only change the height, and make the width in ratio
}


        $destimg=ImageCreateTrueColor($new_width,$new_height) or die('Problem In Creating image2');
        $srcimg=ImageCreateFromJPEG($prod_img) or die('Problem In opening Source Image2');
        ImageCopyResized($destimg,$srcimg,0,0,0,0,$new_width,$new_height,ImageSX($srcimg),ImageSY($srcimg)) or die('Problem In resizing2');
ImageCopyResampled($destimg, $srcimg, 0, 0, 0, 0, $new_width, $new_height, $sizes[0], $sizes[1]) or die('Problem In resampling2');
        ImageJPEG($destimg,$prod_img_thumb,90) or die('Problem In saving2');
        imagedestroy($destimg);
}
[/code]