Disable backspace in firefox, like a page back button

Perhaps someone has come across the fact that when you type in a WYSIWYG editor, when you erase the text in some incredible set of circumstances, the browser may perceive you as a “Back” command and the text will be lost. Moreover, sometimes rather big.
I ran into it today. Therefore, I decided to unzip this action. Fortunately, FireFox allows it.
It is done as follows:
Type about: config in the address bar
Find the setting: browser.backspace_action and switch to 1 .
Now backspace works like kravish, the opposite of the space (scrolling).
Shift + Space = BackSpace
Shift + Backspace = Space
UPD: This is exactly WYSIWYG , which uses an iframe (for example, FCKEditor). IFRAME text is not saved, unlike TEXTAREA