function rb_focus( thing ) {
    thing.style.border = "1px solid black";
    thing.style.backgroundColor = 'lightblue';
}

function rb_blur( thing ) {
    thing.style.border = "1px solid #ccc";
    thing.style.backgroundColor = 'white';
}

function blurMenu( thing ) {
    thing.style.backgroundColor = 'transparent';
}

function focusMenu( thing ) {
    thing.style.backgroundColor = '#000099';
}

function getInternetExplorerVersion()
{
  var rv = -1; // Return value assumes failure.
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}

function checkIE() {
  var browser = navigator.appName;
  var version = parseFloat( navigator.appVersion );
  
  if( browser.indexOf( "Microsoft Internet Explorer" ) != -1 ) 
  {
    var ieVersion = getInternetExplorerVersion();
    if( ieVersion >= 0 && ieVersion < 8 )
      alert( 'For best viewing, please upgrade Internet Explorer to version 8.' );
  }
}