Help me execute this php code. It won't executes

I have this code to add watermark. I tried to run it on my iis7 server but the only thing I get on the screen is the full path of the php script

why is that?

 

put your script text here.

 

<?php 

header('content-type: image/jpeg');  

$watermark = imagecreatefrompng('watermark.png');  
$watermark_width = imagesx($watermark);  
$watermark_height = imagesy($watermark);  
$image = imagecreatetruecolor($watermark_width, $watermark_height);  
$image = imagecreatefromjpeg($_GET['wallpapers/Black_Dog.jpg']);  
$size = getimagesize($_GET['wallpapers/Black_Dog.jpg']);  
$dest_x = $size[0] - $watermark_width - 5;  
$dest_y = $size[1] - $watermark_height - 5;  
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 100);  
imagejpeg($image);  
imagedestroy($image);  
imagedestroy($watermark);  

?>

Code (markup):

the watermark picture and the wallpapers folder located in the same place where the script is.

 

Comment out the header() function and you'll see the errors your script throws

 

it displays blank page no errors

 

From a quick look what is the $_GET in the imagecrate and getimagesize in there for?
You would use get for a variable in the URL since you already have the value of the variable (wallpapers/Black_Dog.jpg) you can place that directly in the tags
try:

<?php 

header('content-type: image/jpeg');  

$watermark = imagecreatefrompng('watermark.png');  
$watermark_width = imagesx($watermark);  
$watermark_height = imagesy($watermark);  
$image = imagecreatetruecolor($watermark_width, $watermark_height);  
$image = imagecreatefromjpeg('wallpapers/Black_Dog.jpg');  
$size = getimagesize('wallpapers/Black_Dog.jpg');  
$dest_x = $size[0] - $watermark_width - 5;  
$dest_y = $size[1] - $watermark_height - 5;  
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 100);  
imagejpeg($image);  
imagedestroy($image);  
imagedestroy($watermark);  

?>

PHP:

 

thanks that solved the problem.
How can I debug php or any other web code?

 

On a linux box, /var/log/httpd usually holds the error_log, from which you can view errors generated by PHP. On a localhost WAMP/EasyPHP/etc, you can find a similar file depending on your setup. It's extremely useful.

 

I found the logs but when I try to open them it says that it already in use. How can I see the logs? maybe with the iis manager?