强制关闭IE窗口

<script language="JavaScript"><!--
function WindowClose()
{
    if(document.all)
    {
        if(parseFloat(window.navigator.appVersion.substr(window.navigator.appVersion.indexOf("MSIE")+5, 3)) < 5.5)
        {
            var str  = '<object id=meizzMax class;
            window.close();
        }
    }
    else    window.close();
}
//--></script>

<input type=button value=关闭 onclick="WindowClose()">