ajax 的post和get写法和调用的对比

=========================Post=========================

var http_request = false;

function send_request(URL,querystr)
{

if(window.XMLHttpRequest)
{
http_request = new XMLHttpRequest();
}

else if(window.ActiveXObject)
{
http_request = new ActiveXObject("Microsoft.XMLHTTP");
}

if(!http_request)
{
window.alert("创建实例失败...");
return false;
}

http_request.onreadystatechange = processRequest;
http_request.open("POST",URL,true);
//http_request.setRequestHeader("Content-Type","text/html;charset=GB2312");
http_request.setRequestHeader("Content-Type","multipart/form-data");//设置正确的GET的enctype
http_request.setRequestHeader("Content-Length", "90000");
http_request.send(querystr);
}

// 处理返回信息的函数
function processRequest()
{
if (http_request.readyState == 4)
{
// 判断对象状态
if (http_request.status == 200)
{
// 信息已经成功返回，开始处理信息
//;
var str=http_request.responseText;
if (sflag==2)
alert(str)

}

else
{
//页面不正常
alert("您所请求的页面有异常。");
}
}
}

调用

function savedata(obj)
{
var updatesql=getupdatesql(obj);
if (!StrIsNull(updatesql))
{
//alert('save:'+updatesql);
var currURL='<%=StrUtil.convUrl("/servlet")%>/DefinedFormSrv?updatesql='+updatesql;

var querystr=null;
send_request(currURL,querystr);

}
}

=========================get=========================

var http_request = false;
var sflag=1;
function send_request(url)
{
//初始化、指定处理函数、发送请求的函数
http_request = false;
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest)
{
//Mozilla 浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType)
{
//设置MiME类别
http_request.overrideMimeType('text/xml');
}
}
else if (window.ActiveXObject)
{
// IE浏览器
try
{
http_request = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e)
{
try
{
http_request = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e)
{
}
}
}
if (!http_request)
{
// 异常，创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
http_request.onreadystatechange = processRequest;
// 确定发送请求的方式和URL以及是否同步执行下段代码
http_request.open("GET", url, true);
//发带参数请求
http_request.send(null);
}
// 处理返回信息的函数
function processRequest()
{
if (http_request.readyState == 4)
{
// 判断对象状态
if (http_request.status == 200)
{
// 信息已经成功返回，开始处理信息
//;
var str=http_request.responseText;
if (sflag==2)
alert(str)

}

else
{
//页面不正常
alert("您所请求的页面有异常。");
}
}
}

调用

function savedata(obj)
{
var updatesql=getupdatesql(obj);
if (!StrIsNull(updatesql))
{
alert('save:'+updatesql);
send_request('<%=StrUtil.convUrl("/servlet")%>/DefinedFormSrv?updatesql='+updatesql);
}
}