刷新页面时如何避免重新上传文件

when i refresh the page, the page will upload again the same file. is there any solution without using header ?

<?php
    if(isset($_FILES['UploadFileField'])){

        $UploadName = $_FILES['UploadFileField']['name'];

        //if the file has the same name, the system will add a random name at in front 
        $UploadName = mt_rand(10000,99999).$UploadName;
        $UploadTmp = $_FILES['UploadFileField']['tmp_name'];
        $UploadType = $_FILES['UploadFileField']['type'];
        $FileSize = $_FILES['UploadFileField']['size'];

        $UploadName = preg_replace("#[^a-z0-9.]#i","",$UploadName);


     //to check the file size, Must be in Kilobyte
        if(($FileSize > 125000)){
            die("error - File too big");
        }

        //If no file Selected   
        if(!$UploadTmp){
        echo "<script>
            alert('Please select a file,'); </script>";
            //die("No file chosen, Please select a file"); 
        }else{
            move_uploaded_file($UploadTmp,"csv/".$UploadName);
            //clearstatcache($UploadTmp);
        } 
    } 

?>

below is the form

<form action="manage_report.php" method="post" enctype="multipart/form-data" id="FileUploadForm">
    <label for="UploadFileField"> <font color="black">
    <input type="file" size="60" name="UploadFileField" id="UploadFileField" accept=".doc"/> </label> </font>
    <span> <input type="submit" name="UploadButton" id="UploadButton" value="Upload" /> </span>
    </form>

thank you in advance