为什么div层中和input中的结果不一样啊，谢谢指教

text.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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head><body>
<?php
echo "kdfjalsfjl";
?>
</body>
</html>
text.html
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head><body>
<script language="javascript">
var xmlhttp;
function createhttp()
{
  if(window.ActiveXObject)
    {
    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    else if(window.XMLHttpRequest)
    {
     xmlhttp=new XMLHttpRequest();
     }
}
 function starthttp()
 {
  createhttp();
  xmlhttp.onreadystatechange=statedo;
  xmlhttp.open("GET","text.xml",true);
  xmlhttp.send(null);
  }
 function statedo()
  {
  
   if(xmlhttp.readystate==4)
    {
      if(xmlhttp.status==200)
        {
            mytext.value=xmlhttp.responsetext;
    xtext.innerHTML=xmlhttp.responsetext;

       }
    }
 }
     </script>
<input type="button"  onclick="starthttp()" />
<div id="xtext"></div>
<textarea type="text" name="mytext" />
</body>
</html>