PHP picture upload and generate thumbnail code

if ($_files[' image '] [' size ']) {
if ($_files[' image '] [' type '] = = "Image/pjpeg") {
$im = @imagecreatefromjpeg ($_files[' image '] [' tmp_name ']);
$n _bmp.= '. jpg ';
}elseif ($_files[' image '] [' type '] = = "Image/x-png") {
$im = @imagecreatefrompng ($_files[' image '] [' tmp_name ']);
$n _bmp.= '. png ';
}elseif ($_files[' image '] [' type '] = = "Image/gif") {
$im = @imagecreatefromgif ($_files[' image '] [' tmp_name ']);
$n _bmp.= '. gif ';
}
Resizeimage ($im, 8888,8888, $n _bmp);
Imagedestroy ($im);
$n _tag = 1;

}

function UploadFile ($STR) {

$save _path = './product/';//File Save directory path

$ext _arr = Array (' rar ', ' zip ', ' jpg ', ' gif ', ' PNG ', ' BMP ');//define file extensions that allow uploads

$max _size = 1000000;//Maximum file size

$file _rand = ';

$file _ext = ';

@mkdir ($save _path, 0777); Change directory Permissions

if ($_files[$str] [' name ']) {//When uploading files

$file _name = $_files[$str] [' name '];//original filename

$tmp _name = $_files[$str] [' tmp_name '];//temporary file name on the server]

$file _size = $_files[$str] [' Size '];//file size

if (@is_dir ($save _path) = = False) {//Check directory
Alert ("The upload directory does not exist.) ",'');
}

if (@is_writable ($save _path) = = False) {//Check directory Write permissions
Alert ("Upload directory does not have write permission.) ",'');
}

if (@is_uploaded_file ($tmp _name) = = False) {//Check if uploaded
Alert ("Temporary file" may not be an upload file.) ",'');
}

if ($file _size > $max _size) {//Check file size
Alert ("Upload file size exceeds limit.") ",'');
}

$temp _arr = Explode (".", $file _name);//Get File name extension
$file _ext = Array_pop ($temp _arr);
$file _ext = Trim ($file _ext);
$file _ext = strtolower ($file _ext);
$file _rand= MD5 (date ("y-m-d"));
if (In_array ($file _ext, $ext _arr) = = False) {//Check extension
Alert ("The upload file name extension is an disallowed extension.") ",'');
}

if (Move_uploaded_file ($tmp _name, $save _path. $file _rand. '. ') $file _ext) = = False) {//Move file
Alert ("Upload file failed.") ",'');
}
}
return $save _path $file _rand. $file _ext;
}


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, './product_e/'. $name);
Imagedestroy ($newim);
}else{
Imagejpeg ($im, './product_e/'. $name);
}
}