as a user requirement I have to disable the backspace button from navigating back in the history. I made the following piece of code

   //Bind back nutton to prevent escaping the page with backspace
  $j(document).unbind('keydown').bind('keydown', function (event) {
   var doPrevent = false;
if (event.keyCode === 8) 
{
    if(event.target == document.body){
        if(event.preventDefault()){ event.preventDefault(); }
        event.stopEvent();
        event.returnValue = false;
    }
}

});

This is working perfectly in all the browsers except IE8/7. I cannot bind the input types as exceptions because the content editor in sharepoint allows to modify the text in div or paragraph elements etc. The solution is not working in IE8 because the event.target returns the element that is on mouseover when there's no controls that has the focus.

All tips will be appreciated. Thanks!!