First part of description is in http://stackoverflow.com/questions/3009001/unsafe-javascript-attempt-to-access-frame-when-try-to-upload-file-with-ajax Problem is that I get access denied error, when try to upload file with ajax-way.
After long debugging I have discovered that everything is working if I don't load ape client. Ape is comet server http://www.ape-project.org/
Ape creates an iframe with src = "http://8.ape.readbox.cz:6969/?...". If I disable ape and this iframe is not created then I have no problem to access document of the iframe, created for ajax-upload.
Togather they looks like
<iframe src="http://8.ape.readbox.cz:6969/?..." style="display: none; position: absolute; left: -300px; top: -300px;" id="ape_undefined"></iframe>
<iframe style="display: none;" id="ValumsAjaxUpload0" src="javascript:false;" name="ValumsAjaxUpload0"></iframe>
Please, can anybody help me? I'm confused.