url uploader

[bob2588]

i am build am url image uploader he only problem i am having is take the url form the forum and placeing it in this code

$content = file_get_contents('$img ');
file_put_contents('/home/sambobi/public_html/bob/b_images/$id.jpg', $content);

the variable $img is the url variable and the $id is random numbers and letter but both parts of this wont works

 

can any one help