xajax+smarty 问题

xajax+smarty 问题 急啊！

我的refreshContent函数调用不了，我已被这个问题困扰了好几天了 ，就是找不到问题出在哪了，希望大家帮我看看，谢谢！
代码如下：

xajax_smarty.php

require_once( 'Config/Config.inc.php');
require_once('xajax/xajax_core/xajax.inc.php');
$xajax = new xajax();
function loadContent($n){
global $Smarty;
if($n==0){
$data[] = array('title' =>'helloworld','content' =>'

what is going on?

');
$data[] = array('title' =>'another item','content' => '

nothing fancy

');
}
else if($n == 1){
echo '=============';
$data[] = array('title' =>'Dynamically loaded' , 'content' => '

There you go

');
}
$Smarty ->assign('posts' ,$data);
$ret = $Smarty ->fetch('post.html');
$Smarty ->clear_all_assign();
return $ret;
}
function refreshContent($formValues){//调用不了
echo "ldkfjdl";
$response= new xajaxResponse();
$newContent = loadContent($formValues['select_page']);
$response ->addAssign('content' , 'innerHTML' , $newContent);
return $response;
}
$xajax ->registerFunction('refreshContent');
$xajax->processRequest();

$Smarty ->assign('content' , loadContent(0));
$Smarty ->assign('xajaxjavascript' , $xajax ->getJavascript('xajax/'));
$Smarty ->display('main.html');
?>

post.html

main.html

Smarty $amp;xajax

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