php自定義urlencode，urldecode函數

//配合JavaScript的ajaxObject函數, 對字串進行轉碼.
function ajax_encode($str){
    $patern = array("/%/","/=/","/&/");// % 必須是第一個項, 替換是按項的順序進行的.
    $rp = array("%25","%26","%3D");
    return preg_replace($patern,$rp,$str);
}
//逆函數
function ajax_decode($str){
    $patern = array("/%25/","/%26/","/%3D/");
    $rp = array("%","=","&");
    return preg_replace($patern,$rp,$str);
}