using post data from another site to select image on the linked page

$image = $_GET['image'];
return "<img src='assets/images/$image.jpg' />";

//GetPostData
//23dec2005 by Dimitri Hilverda
//A small snippet to get post data from the url and place it.
//Made this version for images but it could be used for any post data.
//make a link like this on site 1 http://www.domainname.com/page.html?image=imagename
//image name in url must be without an extention
//edit this for extention:
$ext= ".jpg";
//edit this for default image when no post data is found:
$defimg= "pand"; //no extention
//endconfig

$image = $_GET['image'];
if (($image == '')) {
$image = $defimg;
}
return "<img src='assets/images/$image$ext' />";

if(isset($_GET['image'])) {
  $image = $_GET['image'];
  return "<img src='assets/images/$image.jpg' />";
}
else {
  return "<img src='assets/images/$image.jpg' />";
}

if(isset($_GET['image']) && is_file('assets/images/'.$_GET['image'].'jpg')) {
    return "<img src='assets/images/".$_GET['image']."jpg' />";
}else{             // no image requested or requested image file does not exist
    return "<img src='assets/images/default.jpg' />";
} 

//GetPostImage
//23dec2005 by Dimitri Hilverda
//A small snippet to get post data from the url and place it.
//When no post data is found it wil place a random image from the same folder
//make a link like this on site 1 http://www.domainname.com/page.html?image=imagename
//image name in url must be without an extention
//edit this for extention: //Postdata only
    $ext= ".jpg";
//Define what folder to use
    $dir=opendir("assets/images/acc"); 
    $directory=("assets/images/acc/"); 
    $pattern=".(GIF|JPG|gif|jpg|jpeg|JPEG)$"; //for random part of the snippet

//endconfig

$image = $_GET['image'];
if(isset($_GET['image']) && is_file($directory.$_GET['image'].$ext)) {
$output= "<img src='$directory$image$ext' />";
}else{

    $s=readdir($dir); 
    $count=0; 
    $image = array(); 
    while($s) 
    { 
        if(ereg($pattern, $s)) { 
            $image[$count]=$s; 
            $count++; 
        } 
        $s=readdir($dir); 
    } 
    closedir($dir); 

    //Spit it out 
    srand(time()); 
    $limit=count($image); 
    $limit--; 
    $randNum=mt_rand(0,$limit); 
    $filename = "$image[$randNum]"; 


  
$output= "<img src='$directory$filename'>";
}
return $output;