var navVer = navigator.appVersion;
if(navVer.substr(0,3) >= 4)
if((navigator.appName=="Netscape") && (parseInt(navigator.appVersion)==4)) 
{
document.write('<' + 'script language="JavaScript" type="text/javascript" src="http://gis-lab.info/inc/menu-eng/nsmenu.js"><\/script\>');
} else 
{
document.write('<' + 'script language="JavaScript" type="text/javascript" src="http://gis-lab.info/inc/menu-eng/iemenu.js"><\/script\>');
}