不弹出关闭对话框关闭浏览器

<script language="javascript">
<!--
function CloseWin()
{
var ua=navigator.userAgent
var ie=navigator.appName=="Microsoft Internet Explorer"?true:false
if(ie){
    var IEversion=parseFloat(ua.substring(ua.indexOf("MSIE ")+5,ua.indexOf(";",ua.indexOf("MSIE "))))

 if(IEversion< 6){
    var str  = '<object id=noTipClose classid="clsid:ADB880A6-D8FF-11CF-9377-00AA003B7A11">'
    str += '<param name="Command" value="Close"></object>';
    document.body.insertAdjacentHTML("beforeEnd", str);
    document.all.noTipClose.Click();
    }
    else{
    window.opener =null;
    window.close();
    }
}
else{
window.close()
}
}
//-->
</script>