automatic image resize

/* resizeToFile resizes a picture and writes it to the harddisk
 * 
 * $sourcefile = the filename of the picture that is going to be resized
 * $dest_x      = X-Size of the target picture in pixels
 * $dest_y      = Y-Size of the target picture in pixels
 * $targetfile = The name under which the resized picture will be stored
 * $jpegqual  = The Compression-Rate that is to be used
 */

function resizeToFile ($sourcefile, $dest_x, $dest_y, $targetfile, $jpegqual)
{
  

/* Get the dimensions of the source picture */
   $picsize=getimagesize("$sourcefile");

   $source_x  = $picsize[0];
   $source_y  = $picsize[1];
   $source_id = imageCreateFromJPEG("$sourcefile");

/* Create a new image object (not neccessarily true colour) */
      
   $target_id=imagecreatetruecolor($dest_x, $dest_y);

/* Resize the original picture and copy it into the just created image
   object. Because of the lack of space I had to wrap the parameters to
   several lines. I recommend putting them in one line in order keep your
   code clean and readable */
      

   $target_pic=imagecopyresampled($target_id,$source_id,
                                   0,0,0,0,
                                   $dest_x,$dest_y,
                                   $source_x,$source_y);

/* Create a jpeg with the quality of "$jpegqual" out of the
   image object "$target_pic".
   This will be saved as $targetfile */
 
   imagejpeg ($target_id,"$targetfile",$jpegqual);

   return true;

}