PHP simple and practical to generate thumbnail code

This program is based on the user upload pictures and then upload the picture proportionally generated thumbnails

$w? $resizewidth = $w: $resizewidth =400;//to generate the width of the picture


$h? $resizeheight = $h: $resizeheight =400;//to generate the height of the picture


function Resizeimage ($im, $maxwidth, $maxheight, $name) {


$width = Imagesx ($im);


$height = Imagesy ($im);


if ($maxwidth && $width > $maxwidth) | | ($maxheight && $height > $maxheight)) {


if ($maxwidth && $width > $maxwidth) {


$widthratio = $maxwidth/$width;


$resizewidth =true;


        }


if ($maxheight && $height > $maxheight) {


$heightratio = $maxheight/$height;


$resizeheight =true;


        }


if ($resizewidth && $resizeheight) {


if ($widthratio < $heightratio) {


$ratio = $widthratio;


}else{


$ratio = $heightratio;


            }


}elseif ($resizewidth) {


$ratio = $widthratio;


}elseif ($resizeheight) {


$ratio = $heightratio;


        }


$newwidth = $width * $ratio;


$newheight = $height * $ratio;


if (function_exists ("imagecopyresampled")) {


$newim = Imagecreatetruecolor ($newwidth, $newheight);


Imagecopyresampled ($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);


}else{


$newim = imagecreate ($newwidth, $newheight);


imagecopyresized ($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);


        }


imagejpeg ($newim, $name);


Imagedestroy ($newim);


}else{


imagejpeg ($im, $name);


    }


}

If ($_files[' uploadfile '] [' size ']) {
    if ($_files[' uploadfile '] [' type '] = = "Image/pjpeg") {
        $im = imagecreatefromjpeg ($_files[' uploadfile '] [' tmp_name ']);
   }elseif ($_files[' uploadfile '] [' type '] = = "Image/x-png") {
         $im = imagecreatefrompng ($_files[' uploadfile '] [' tmp_name ']);
   }elseif ($_files[' uploadfile '] [' type '] = = "Image/gif") {
         $im = imagecreatefromgif ($_files[' uploadfile '] [' tmp_name ']);
   }
    if ($im) {
        if (file_exists (' bbs.jpg ')) {
            unlink (' bbs.jpg ');
       }
        resizeimage ($im, $resizewidth, $resizeheight, ' bbs.jpg ');
    &NBsp;   Imagedestroy ($im);
 
   }
}
//$uploadfile = "www.jzread.com.jpg";
?