function trim(s)
{
  if (s)
    return s.replace(/(^\s+)|(\s+$)/g, "");
  else
    return '';
}

function empty(s)
{
    if(trim(s) == '')
          return true;
    return false;
}

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 = window.document.title;
 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 = url+','+title;
  return true;
 }
 else if (b.type == "Netscape") window.sidebar.addPanel(title,url,"");
 else alert("Нажмите CTRL-D, чтобы добавить страницу в закладки.");
 return false;
}