简易聊天室案例（采用Ajax技术）
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link href="css/bootstrap.min.css" rel="stylesheet">
<script type="text/javascript">
document.onkeydown=function(){
if(event.keyCode==13){
postData();
}
}
function postData(){
//获取发言内容
var yourWords=document.getElementById("yourWords").value;
//alert("yourWords=="+yourWords);
if(yourWords==""){
alert("请您输入内容");
return false;