function getBrowserInfo() {
 var t,v = undefined;
 if (window.opera) t = 'Opera';
 else if (document.all) {
 t = 'IE';
 var nv = navigator.appVersion;
 var s = nv.indexOf('MSIE')+5;
 v = nv.substring(s,s+1);
 }
 else if (navigator.appName) t = 'Netscape';
 return {type:t,version:v};
}
 
function bookmark(a){
 var url = window.document.location;
 var title = 'Интересный материал от www.4user.org';
 var b = getBrowserInfo();
 if (b.type == 'IE' && 7 > b.version && b.version >= 4) window.external.AddFavorite(url,title);
 else if (b.type == 'Opera') {
 a.href = url;
 a.rel = "sidebar";
 a.title = title;
 return true;
 }
 else if (b.type == "Netscape") window.sidebar.addPanel(title,url,"");
 else alert("������� CTRL-D, ����� �������� �������� � ��������.");
 return false;
}