Ajax请求

function ajaxFunction()
{
var xmlHttp;

try
    {
   // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
    }
catch (e)
    {
  // Internet Explorer
   try
      {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
      }
   catch (e)
      {
      try
         {
         xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
         }
      catch (e)
         {
         alert("您的浏览器不支持AJAX！");
         return false;
         }
      }

      xmlHttp.onreadystatechange = function () {
            if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
                // 返回值xmlHttp.responseText;
                成功返回后的处理
            }
        }

    }
}



// GET方式
xmlhttp.open("GET","demo_get2.asp?fname=Bill&lname=Gates",true);
xmlhttp.send();
// POST方式
xmlhttp.open("POST","ajax_test.asp",true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xmlhttp.send("fname=Bill&lname=Gates");