php改變上傳後圖檔的長寬尺寸

<?php


if(is_uploaded_file($upload1))

//upload1為上傳圖檔input 欄位內的name""
          {
          if($_FILES['upload1']!="none")  {      
                //resize 390*250  518×351  2
$uploadedfile = $_FILES['upload1']['tmp_name'];
$src = imagecreatefromjpeg($uploadedfile);
list($width,$height)=getimagesize($uploadedfile);
$newwidth=390 ;
$newheight=($height/$width)*$newwidth;
$tmp=imagecreatetruecolor($newwidth,$newheight);
imagecopyresampled($tmp,$src,0,0,0,0,$newwidth,$newheight,$width,$height); 

                $fnsub=explode(".",$_FILES['upload1']['name']);

                if($fnsub[1]!="") {
                $fn1="bbs_".date("Ymdhis").".".$fnsub[1];
                copy($_FILES['upload1']['tmp_name'],$DOCUMENT_ROOT."/upimg/$fn1");
             
                imagejpeg($tmp,$DOCUMENT_ROOT."/upimg/$fn1",100);
                imagedestroy($src);
imagedestroy($tmp);
             }                  
} 
          } 


?>