Tooltip.prototype = new _Popup();

function Tooltip(width) {
  this.base(width);
  this.base_display = this.display;
  
  this.displayDelay = NODELAY;
  this.div.className = 'plx_tooltip';
  this.div.style.zIndex += 10;
  
  this.display = function(content, width) {
    this.base_display(content, null, null, width);
  }
}

var globalTooltip = new Tooltip();