window.addeventlistener in google chrome

[wpjoju]

i have this code which adds an event listener to a newly opened window but it doesn't seem to work in google chrome. the problem is window.addEventListener seem to work in chrome but if you do something like var win = window.open(); win.addEventListener... it doesn't seem to work, see my code below

exportwin = window.open('ExportScreeningSafetyReport.aspx?qsid=' + qsid + '&title=' + title + (format ? '&format=' + format : ''));
attachEventsMask(exportwin, format);
 
attachEventsMask = function(wins, format)
{
    if (wins.attachEvent)
{
    showWindowMask('', 'Loading...');
    if (format == 'word')
        wins.attachEvent("onbeforeunload", triggerClose );
    else
    {
        wins.attachEvent("onload", triggerClose );
        wins.attachEvent("onbeforeunload", triggerClose );
    }
}
else if (wins.addEventListener)
{
    showWindowMask('', 'Loading...');
    if (format == 'word')
        wins.addEventListener("beforeunload", triggerClose, false);
    else
    {
        wins.addEventListener("load", triggerClose, false);
        wins.addEventListener("beforeunload", triggerClose, false);
    }
}
}