PHP --- ajax が POST 値 (html タグを含む) を送信ページに渡し、データが失われるか文字化けする

<code><span>var</span> content = UM.getEditor(<span>'myEditor'</span>).getAllHtml();
<span>/*对待传递的值的内容进行编码*/</span><span>var</span> htmlcontent = <span>encodeURIComponent</span>(content);
alert(htmlcontent);
<span>var</span> postStr = <span>'news_title='</span> +　news_title +<span>'&htmlc/span> + htmlcontent + <span>'&sid='</span>+<span>Math</span>.random();
alert(postStr);
ajax(<span>"../news_submit_hand.php"</span>,postStr,<span><span>function</span><span>(result)</span>{</span><span>if</span>(result == <span>'submit_success'</span>){
        alert(<span>"新闻提交成功！请通过右上角的关闭按钮来关闭编辑器。"</span>);          
    }
    <span>else</span> {
        alert(<span>"新闻提交出错！"</span>);            
    }      
});</span></code>

<code><span><span>function</span><span>str_insert</span><span>(<span>$str</span>, <span>$i</span>, <span>$substr</span>)</span>
{</span><span>for</span>(<span>$j</span>=<span>0</span>; <span>$j</span><<span>$i</span>; <span>$j</span>++){
     <span>$startstr</span> .= <span>$str</span>[<span>$j</span>];
}
<span>for</span> (<span>$j</span>; <span>$j</span><strlen(<span>$str</span>); <span>$j</span>++){
    <span>$laststr</span> .= <span>$str</span>[<span>$j</span>];
}
    <span>$str</span> = (<span>$startstr</span> . <span>$substr</span> . <span>$laststr</span>);
    <span>return</span><span>$str</span>;
} 


<span>$myfile</span> = fopen(<span>$news_path</span>, <span>"w"</span>);
<span>if</span>(<span>'FALSE'</span> == <span>$myfile</span>)<span>echo</span><span>'error'</span>;
<span>/*处理新闻标题等信息*/</span><span>//待插入的html代码</span><span>$insert_html</span> = <span>"<div><h3 style=\"text-align:center;\">". <span>$news_title</span> . <span>"</h3><div style=\"text-align:center;width:100%;font-size:8px;color:#A9A9A9;\"><span>发布者：admin</span>  <span>发布日期："</span>. date(<span>"Y-m-d H:i:s"</span>,<span>$timestamp</span>) .<span>"</span></div></div><hr style=\"border:1px dashed #000; height:1px\">"</span>;

<span>$first_pos</span> = stripos(<span>$htmlcontent</span>, <span>"%3Cbody%20%3E"</span>);
<span>$first_pos</span> += <span>13</span>;
<span>$content</span> =str_insert(<span>$htmlcontent</span>,<span>$first_pos</span>,<span>$insert_html</span>);

fwrite(<span>$myfile</span>, <span>$content</span>);
fclose(<span>$myfile</span>);</code>