<form name="photo" enctype="multipart/form-data" action="<?php echo $_SERVER["PHP_SELF"];?>" method="post">
    Photo <input type="file" name="image" size="30" />
          <input type="submit" name="upload" value="Upload" />
</form>

if (isset($_POST["upload"])) {
    //Get the file information
    $userfile_name = $_FILES['image']['name'];
    $userfile_tmp = $_FILES['image']['tmp_name'];
    $userfile_size = $_FILES['image']['size'];
    $userfile_type = $_FILES['image']['type'];
    $filename = basename($_FILES['image']['name']);
    $file_ext = strtolower(substr($filename, strrpos($filename, '.') + 1));

    //Only process if the file is a JPG, PNG or GIF and below the allowed limit
    if((!empty($_FILES["image"])) && ($_FILES['image']['error'] == 0)) {

        foreach ($allowed_image_types as $mime_type => $ext) {
            //loop through the specified image types and if they match the extension then break out
            //everything is ok so go and check file size
            if($file_ext==$ext && $userfile_type==$mime_type){
                $error = "";
                break;
            }else{
                $error = "Only <strong>".$image_ext."</strong> images accepted for upload<br />";
            }
        }
        //check if the file size is above the allowed limit
        if ($userfile_size > ($max_file*1048576)) {
            $error.= "Images must be under ".$max_file."MB in size";
        }

    }else{
        $error= "Select an image for upload";
    }
    //Everything is ok, so we can upload the image.
    if (strlen($error)==0){

        if (isset($_FILES['image']['name'])){
            //this file could now has an unknown file extension (we hope it's one of the ones set above!)
            $large_image_location = $large_image_location.".".$file_ext;
            $thumb_image_location = $thumb_image_location.".".$file_ext;

            //put the file ext in the session so we know what file to look for once its uploaded
            $_SESSION['user_file_ext']=".".$file_ext;

            move_uploaded_file($userfile_tmp, $large_image_location);
            chmod($large_image_location, 0777);

            $width = getWidth($large_image_location);
            $height = getHeight($large_image_location);
            //Scale the image if it is greater than the width set above
            if ($width > $max_width){
                $scale = $max_width/$width;
                $uploaded = resizeImage($large_image_location,$width,$height,$scale);
            }else{
                $scale = 1;
                $uploaded = resizeImage($large_image_location,$width,$height,$scale);
            }
            //Delete the thumbnail file so the user can create a new one
            if (file_exists($thumb_image_location)) {
                unlink($thumb_image_location);
            }
        }
        //Refresh the page to show the new uploaded image
        header("location:".$_SERVER["PHP_SELF"]);
        exit();
    }
}

$('#uploadBtn').live('click', function(){
        var data = "upload=true";
        $.ajax({
            type: "POST",
            url: "process.php",
            data: data,
            cache: false,
            success: function(data){
            }
        });
    });