Moving File Input To Different Form Doesn't Work In IE7

I have form inside iframe. I want to copy form to parent window after user entered data and then submit. Everything works fine, except with file input. It seems impossible to move file input(after user selected file) to different form in different document (only ie7). Here is javascript code im using inside iframe to move form elements:

Code:

var parentForm = parent.document.getElementById('editGallerieFormParent');
parentForm.ordering.value = form.ordering.value;
parentForm.catname1.value = form.catname1.value;
parentForm.description.value = form.description.value;

[Code]....