i'm trying to make a cms wherein an admin user can edit a content including one image using PHP. my question involves a problem encountered with the way IE redisplay the edited content. even if the image for the content has already been changed and saved in the database, IE still displays the original image associated with the content. the change does not happen until i manually clear the browser cache. an exception is with IE6 which displays it fine. all other browsers do not have any problem.

i tried sending
PHP Code:
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past 
but it doesn't appear to have any effect. the problem only involves all IE except IE6.

any suggestions would be appreciated. thanks.