Disabling the back button in PeopleSoft

I was asked to disable the back button in the browser for ePerformance. However, based on my research you I concluded that the back button cannot be disabled and nor would I want to disable it if I could.  So what can you do to prevent users from losing their work, by using the back button in PeopleSoft?  The answer appears to be the onbeforeunload event in the browser.  This event is designed to prompt the user if they really want to leave the page and potentially lose their changes.  To implement this I needed to add the following JavaScript to the page I wanted to prevent the user from losing their changes.

1. Modify the onbeforeunload to warn the user if the page has changed and they are navigating away from the page.
window.onbeforeunload = function(e) {
           var changes = checkFormChanged(document.%formname);
if (changes)
{           
  return "You have unsaved changes, please save them."
}
}

2.add some JavaScript to clear out the onbeforeunload if they user selected a link/button on the page.
function adaptLinks() {
    var links = document.getElementsByTagName('a');
    for (i = 0; i != links.length; i++) {
        links[i].onclick = (function () {
            var origOnClick = links[i].onclick;
            return function (e) {
                 window.onbeforeunload = function(){};
                if (origOnClick != null && !origOnClick()) {
                    return false;
                }               
            }
        })();
    }
}
adaptLinks();


3.  Finally, I  Monkey Patched the endModalCntrl to clearout the onbeforeunload if they used the "X" to close out a modal window. 

 (function() {
  var originalendModalCntrl = ptCommonObj.endModalCntrl;
  ptCommonObj.endModalCntrl = function() {
    window.onbeforeunload = function(){};
    return new originalendModalCntrl();
  }
})();

Special thanks to Jim Marion for #3

Now when the user clicks the back button or changes the url they are prompted by the page that they have unsaved changes, like this: