codice:
<script>	window.onload = function() {
		document.getElementById("uploadForm").onsubmit = function() {
			document.getElementById("uploadForm").target = "uploadIframe";
			document.getElementById("uploadIframe").onload = function() {
				var response = eval("(" + frames['uploadIframe'].document.getElementsByTagName("body")[0].innerHTML + ")");
				alert(response.msg);
			}
		}
	};
</script>


<form id="uploadForm" action="upload.php" enctype="multipart/form-data" method="post">
	<input name="image" type="file" />
	<input type="submit" />
</form>


<iframe style="visibility: hidden;" id="uploadIframe" name="uploadIframe" src=""></iframe>
L'alert su Opera, FF e Chrome viene stampato, su IE no...