Javascript in article, HTML element resaults in Error 403

Hi. This is my first post, so hello to everyone :).

I have small problem with my Contao. I have article, element type: HTML. Inside I have some HTML code and part like this:

HTML Code:

---

<a class="ce_backlink links" title="Zurück zur vorherigen Seite" href="j a v ascript:history.go(-1)">Zurück</a>

---

*On this forum javascript:... is blocked, that's why i have "javascript" with spaces in HTML part.

When I try to save this code - I get Error 403, and data is not saved in database. It looks like on some level (php, mysql, server configuration) there is part searching for javascript and if it find it - it blocks site. Yes, I know that I can use {{link::back}}, but I'm making translation of existing site, so trying to leave as much of oryginal structure as possible.

I can add that my files are stored on hosting firm servers, so I can't mess too much in backend.

Questions are: Have you ever seen this problem before, what is wrong and can I fix it in Contao?

This is probably a security feature of your hoster, preventing any JavaScript to be sent to the server via POST Requests.