文件上传iframe实现ajax

<iframe id="frameId" name="ajaxFileLoad" style="display:none;"></iframe>

<form name="form1"  action="action.do" method="post" enctype="multipart/form-data" target="ajaxFileUpload">

<input id="file" type="file" name="file" value="上传">

</form>

js:

document.form1.submit();

var hiddenIframe = document.getElementById("frameId");

var content = hiddenIframe .contentWindow ?  hiddenIframe .contentWindow : hiddenIframe .content;

if(content .document.getElementById("msgInfo")==null){

setTimeout("getMsgInfo()",1000);

}

function getMsgInfo(){

var hiddenIframe = document.getElementById("frameId");

var content = hiddenIframe .contentWindow ?  hiddenIframe .contentWindow : hiddenIframe .content;

var getMsgInfo;

if(content .document.getElementById("msgInfo")==null){

getMsgInfo =  setInterval("getMsgInfo()",1000);

}else{

clearInterval(getMsgInfo);

}

}

action:

getResponse().setContentType(text/html);

try{

msg = "<div id='msgInfo'>"+msg+"</div>";

getResponse().getWriter().write(msg);

}catch(){

}