Image upload takes previous temp file to upload in php

Here i have the problem with uploading image in php.

The problem is that when first time i upload the image file it works fine. But when i am trying to upload the file second time without page refresh it takes first image name and upload it.

Anybody can tell me what the problem and how can it resolve ?

$name = $_FILES['ImageFile']['name'];

$size = $_FILES['ImageFile']['size'];

$tmp = $_FILES['ImageFile']['tmp_name'];



$path = "public/www/uploads/";

        $valid_formats = array("jpg", "png", "gif", "bmp");

        $response = '';

        if(strlen($name)) {



            list($txt, $ext) = explode(".", $name);

            if(in_array($ext,$valid_formats)) {



                if($size<(1024*1024)) {



                    $actual_image_name = time().substr(str_replace(" ", "_", $txt), 5).".".$ext;

                    if(move_uploaded_file($tmp, $path.$actual_image_name)) {



                                                $response = "<img src='public/www/uploads/".$actual_image_name."?parm=".time()."' class='preview'>";



                    } else { 

                        $response = "failed";

                    }

                } else { 

                    $response = "Image file size max 1 MB";                 

                }

            } else {

                $response = "Invalid file format..";    

            }

        } else {

            $response = "Please select image..!";

        }

here response is a variable that used to get status.