Navigation, Previous Button

[VictorR]

Hello Lay-team,

My website contain a lot of projects which are classified by categories. Some projects are in different categories.
I would like to do a previous button (just like any browser previous button) in every project that goes back to the previous page and not to an actual category because for some project there are different categories involved and moreover it’s not convenient to edit the links project by project when you have more that a hundred of it…

I’ve tried a php code :
<a href="<?php echo $_SERVER['HTTP_REFERER'] ?>">Back</a>

But it actually goes back to the homepage with an ugly permalink :
<?php%20echo%20$_SERVER[%27HTTP_REFERER%27]%20?>

I’m not an expert at all in Php and the code might be wrong…
I’ve tried also in Javascript but it didn’t work as well…

Do you have any solution to do that ?

Thank you in advance,
Victor R