IE8 local storage event fires in document not in window. Why this is different?

Question

$(document).bind('storage', function (e) {
    if(!document.hasFocus() && localStorage.getItem("MapLoginStatus") == "false"){
         //// action
    }    
});

This works in IE8 not in chrome.

$(window).bind('storage', function (e) {
    if(!document.hasFocus() && localStorage.getItem("MapLoginStatus") == "false"){
        //// action
    }  
});

This works in Chrome not in IE8

How to identify, which one works? Is there any functions like localStorage.inside(window) - or something like that?

Thanks.