Upload script - file type not working in IE but fine in others

1

My upload script wont work in IE, it gives the error that only png, jpeg, jpg etc can be uploaded.

this is the script i am using,

}
if ($HTTP_POST_FILES['img1']['type'] != "image/gif" AND
$HTTP_POST_FILES['img1']['type'] != "image/jpg" AND
$HTTP_POST_FILES['img1']['type'] != "image/jpeg" AND
$HTTP_POST_FILES['img1']['type'] != "image/png" AND !isset($error)) {
	$error = "<b>You may only upload .gif, .jpg and.png files.</b><br><br>";
	unlink($HTTP_POST_FILES['img1']['tmp_name']);

It works perfect in safari and firefox!!!

If anyone can help would be great!!

also is there a script where I can make it only accept images with a certain dimension? or it resizes the image??

thanks

stu