Previously, I use Apache1.3+php4.3. Then, no such problem comes out.
Thanks.
//ajaxtest.php
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<HTML>
<HEAD>
<script type="text/javascript" src="prototype.js"></script>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /
>
<TITLE> New Document </TITLE>
</HEAD>
<body class="bg">
<div id="main" class="main"></div>
<script>
var myaj = new Ajax.Updater('main','http://address/test/test1/
inphp.php',{evalScripts:true,onComplete:function(req)
{alert(req.responseText);}});
</script>
</body>
</html>