A iframe hidden with display:none style does not seem to be able to act as a target for forms: <iframe name="myiframe" style="display: none;"></iframe> <form action="url.html" target="myiframe" method="post"> <input type="submit"/> </form> Instead of loading url.html in myiframe it pops up a new window where it loads the page. In Internet Explorer, Firefox (1.5) and Opera this works as expected, the page is loaded inside the iframe. A side bug(?), if the iframe is visible, and the page loads, a specified onLoad function is not executed (shall it? IE/Firefox does it, opera unknown).