ajax 简单实现判断用户是否注册【登录情况】【员工注册、上拉动态加载】 _Ajax

ajax 简单实现判断用户是否注册【登录情况】【员工注册、下拉动态加载】
   ajax 实现注册检测及员工注册 javascript ：
<script>
//检测用户是否被注册
function check()
{
    var name = document.getElementById("empName").value;
    //1.创建核心对象
    var request = false;
    try
    {
      request = new XMLHttpRequest();//firefox
    }
    catch(e)
    {
       request = new ActiveXObject("Microsoft.XMLHttp");
    }
    //2.打开并发送(加随机数，也不会访问缓存)
    request.open("get","ajax.do?p=check&name="+name+"&r="+Math.random());
    request.send(null);
    //3.接收
    request.onreadystatechange = function()
    {
      if (request.readyState==4 && request.status==200)
      {
        var ret = request.responseText;
       //alert(ret.length);
        if (ret=="true")
        {
          document.getElementById("msg").innerHTML="手气真被";
        }
       if(ret!="true")
        {
          document.getElementById("msg").innerHTML="手气真好";
        }
      }
    }
}

//加载事件去查所有部门，得到是部门json数组字符，要转换，并添加select
onload = function()
{
     //1.创建核心对象
    var request = false;
    try
    {
      request = new XMLHttpRequest();//firefox
    }
    catch(e)
    {
       request = new ActiveXObject("Microsoft.XMLHttp");
    }
    //2.打开并发送(加随机数，也不会访问缓存)
    request.open("get","ajax.do?p=getAllDept&r="+Math.random());
    request.send(null);
    //3.接收
    var dep = document.getElementById("dep");
    request.onreadystatechange = function()
    {
      if (request.readyState==4 && request.status==200)
      {
        var ret = request.responseText;
        var arry = eval("("+ret+")");
        for (var i=0;i<arry.length;i++)
        {
           var op = new Option(arry[i].name,arry[i].id);
           dep.add(op);
        }
      }
    }
}
</script>

//body代码

<body> 
   
   <form action="ajax.do?p=regist" method="post">
       姓名:<input type=text name="empName" id="empName" onblur="check()"> <span id="msg"></span><br>
      性别:<input type=radio name="empSex" value=1>男
          <input type=radio name="empSex" value=0>女 <br>

      部门:<select id="dep" name="dep">
          </select>

          <br>
          <input type=submit value="注册">
   </form>
</body>

//---源码采用hibernate 单独实现ajax 在这里没有整合spring、struts---------------------------------

// 下面是 json生成方式做参考
<script>
   //json对象   javascript object native(javascript本地原生对象)
   var json1 = {id:1,name:"张三",sex:"男"};

   //json数组
   var arry = [
                 {id:1,name:"张三",sex:"男"},
                 {id:2,name:"李四",sex:"女"},
                 {id:3,name:"王五",sex:"男"}

               ];

   var json2 = "{id:4,name:'赵六',sex:'男'}";
   //把字符串转json
   var json3 = eval("("+json2+")");
   alert(json3.name);


   for (var i =0;i<arry.length;i++)
   {
     alert( arry[i].sex );
   }
</script>