ajax 使用

来源：互联网发布：大理旅游攻略知乎编辑：程序博客网时间：2024/05/30 22:58

var request;
function createRequest()
{
    try{
        request=new XMLHttpRequest();
    }catch(trymicrosoft)
    {
        try{
            request=new ActiveXObject("Msxml2.XMLHTTP");
        }catch(othermicrosoft)
        {
            try{
                request=new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch(failed)
            {
                request=false;
            }
        }
    }
    if(!request)
    {
       alert("err Happend!");
       return null;
    }
    return request;
}

//根据行业大类1显示行业大类2
function selectOccp_1()
{
    //var username=document.getElementById("username").value;
    var occp_1 = document.forms[0].occp_1.value;
    var url="<%=request.getContextPath()%>/pub/getOccCata2.do";
    request = createRequest();
    request.open("POST",url,false);
    request.onreadystatechange=disResultOccp_1;//隐性的循环
    request.setrequestheader("cache-control","no-cache");
request.setrequestheader("Content-Type","application/x-www-form-urlencoded");
    post = "occp_1=" + occp_1;
    post = encodeURI(post);
    post = encodeURI(post);//两次，很关键

    request.send(post);
}
function disResultOccp_1()
{
    if(request.readystate==4)
    {
        if(request.status==200)
        {
            var temp = "<select name='occp_2' style='width:152px' onchange='selectOccp_2();' >"
            temp+=request.responseText;;
            temp+="</select>";
            document.getElementById("div_occp_2").innerHTML = temp;

            document.getElementById("div_occp_3").innerHTML = "<select name='occp_3' style='width:152px' onchange='selectOccp_3();' ><option value=''>--请选择--</option></select>";
            document.forms[0].occ_code.value = "";
        }
        else
        {
           alert('Something Wrong has Happend!');
        }
    }
}