Expanding a image function

[refiking]

I have a function that works for jpg.  I want it to do the same exact thing for gif and png, but I am failing at it currently and am not sure why.  Can you tell me what is wrong with my modifications?

 

Original Functioning Code

function easyResize($img_sourse, $save_to, $quality, $width) { 
$size = GetImageSize($img_sourse); 
$im_in = ImageCreateFromJPEG($img_sourse); 

$new_height = ($width * $size[1]) / $size[0]; // Generate new height for image
$im_out = imagecreatetruecolor($width, $new_height); 

fastimagecopyresampled($im_out, $im_in, 0, 0, 0, 0, $width, $new_height, $size[0], $size[1]); 

ImageJPEG($im_out, $save_to, 100); // Create image
ImageDestroy($im_in); 
ImageDestroy($im_out); 
}

 

Modified Nonworking Code

function easyResize($img_sourse, $save_to, $quality, $width) { 
$size = GetImageSize($img_sourse); 
$pos = strpos($img_sourse, 'jpg');
IF ($pos !== false){
$im_in = ImageCreateFromJPEG($img_sourse); 
}
$pos2 = strpos($img_sourse, 'gif');
IF ($pos2 !== false){
$im_in = imagecreatefromgif($img_sourse);
}
$pos3 = strpos($img_sourse, 'png');
IF ($pos3 !== false){
$im_in = imagecreatefrompng($img_sourse);
}
$new_height = ($width * $size[1]) / $size[0]; // Generate new height for image
$im_out = imagecreatetruecolor($width, $new_height); 

fastimagecopyresampled($im_out, $im_in, 0, 0, 0, 0, $width, $new_height, $size[0], $size[1]); 
echo $img_sourse . '<br>' . $im_in . '<br>' . $im_out; exit;
IF ($pos !== false){
ImageJPEG($im_out, $save_to, 100); // Create image
}
IF ($pos2 !== false){
imagegif($im_out, $save_to);
}
IF ($pos3 !== false){
imagepng($im_out, $save_to);
}
ImageDestroy($im_in); 
ImageDestroy($im_out); 
}