access denied using ie when upload file

That's right, avoid form.submit() if you can. (And 99% of the time, you can.) IE (especially IE7) takes a lot of extra security precautions when a script in one frame tries to invoke certain actions (such as form submission) in another frame. Instead, have the user click a "submit" button and cancel (if necessary) using an "onsubmit" handler attached to the form, instead of validating and then submitting.

Although browsers can be difficult, there are many ways to get the job done. If your first approach doesn't work there are probably several others that will.

 

转自：http://bytes.com/topic/javascript/answers/602230-problem-ie-ajax-file-upload-via-iframe-javascript-error-access-denied-zugriff-verweigert