function check()
{
if(document.layers){document.location.href="html_metal.htm";}
else if (navigator.userAgent.indexOf('Opera') > -1) {
    version = navigator.userAgent.substring(navigator.userAgent.indexOf('v'));
    {document.location.href="html_metal.htm"};
}
else{document.location.href="dhtml_index.htm";}
}