Problem when save a page

Why when I enter text with an apostrophe and save the page, it adds a slash?

For example:

Nell’esempio becomes Nell\’esempio

I am inserting content with the TinyMCE editor disabled.

Check whether magic quotes is activated. If it is on I advise on deactivating it if you can. I’m confident that it will resolve your issue.

It is an old apache/php function meant to make sql queries secure. In sql queries quotes can be a risk and a cause for errors. What it does is it prefixes all quotes sent to the server with a slash.

Read more on php.net

Thanks. Problem solved.