Cache problem after sending a html-form

in some part of my webpage i allow my users to change their profile picture. This is made simple by a form with the element <input type="file" name="avatar" id="avatar" />. After they upload the开发者_如何转开发 photo a php script is called were all the image checking and processing is made. When everything is ok, the previous user image is deleted and changed by the new one (with the same name) and then the user is redirected to their profile page.

The problem is, when the user change his picture, the firts time he goes to his profile page (when is redirected by the upload script) the picture is not the new one, is a cached copy of the old one, after a few f5 (reloads) the new image is showed.

A while ago a have a similar problem with an rss parser i made in php, if i call the url feed sometimes instead of a new version of the feed, i got a cached version. I solved this problem just by generating a ramdom number every time i needed the feed and then adding it to the url like; www.page.com/thefeed.rss?var=#ramdom_number

But, i really dont want to implement this "solution" because is unprofessional and my users will see the url with that parameter.

This is a resume of the upload operation:

profile.php?i=mycv : In this page is all the user data included the actual profile picture and the form to upload a picture, the form makes a post call to image_handler.php

image_handler.php : Is a php script who process the image sended by profile.php?i=mycv and is everything is ok, the user is redirected to profile.php?i=mycv.

Thanks for any help!

Try this code in profile.php

<?php
$act = $_GET["a"];

 if($a == "return"){
 header("location:profile.php?i=mycv");
 }
?>

And then change url in image_handler.php that it sends user to profile.php?a=return page instead of profile.php?i=mycv

If that does not work you can add like this: <img src="http://someplace.com/someimage.png?<?php print time(); ?>"> then user cannot see the number part.