window.onload = function(){
    if (!(window.ActiveXObject) && "ActiveXObject" in window) {
        if (document.cookie.indexOf("ie_behavior=") < 0) {
            document.getElementById("IE-overlay").style.display = "block";
        }
    }

    document.getElementById("IEOverlay_close").addEventListener("click", function(){
        var date = new Date();
        date.setTime(date.getTime()+(5*60*1000));
        var expires = "; expires="+date.toGMTString();
        document.cookie = "ie_behavior"+"="+"1"+expires+"; path=/";

        document.getElementById("IE-overlay").style.display = "none";
    });
};