PHP中遇到AJAX的有关问题

<?php<br />header("Content-Type:html/text;Charset=utf-8");<br />$name = $_POST['name'];<br />$email = $_POST['email'];<br />$comment = $_POST['comment'];<br />$fh = @fopen("14-6.txt","ab");<br />fwrite($fh,"姓名:".$name,strlen($name));<br />fwrite($fh,"email:".$email,strlen($email));<br />fwrite($fh,"评论:".$comment,strlen($comment));<br />fclose($fh);<br />echo 1;<br />?>

function $(id){<br />	return document.getElementById(id);<br />}<br />function addcomment(){<br />	var url = "14-6.php";<br />	var status = document.getElementById("divmsg");<br />	status.value="正在提交》》》";<br />	var param = "name="+$("name").value+"email="+$("email").value+"comment="+$("comment").value;<br />	xmlhttp_request.onreadystatechange = function(){<br />		if(xmlhttp_request.readyState==4 && xmlhttp_request.status == 200){//相应完全显示信息<br />			alert (xmlhttp_request.responseText);<br />			if(xmlhttp_request.responseText == "1"){<br />				status.value = "发表成功！！";<br />				$("name").value="";<br />				$("email").value="";<br />				$("comment").value="";<br />			}else{<br />				status.value = "发表失败！请重新发表！";<br />			}<br />		}	<br />	}<br />	xmlhttp_request.open("POST",url,true);<br />	xmlhttp_request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");//设置头信息<br />	xmlhttp_request.send(param);<br />}