function xtcLava(o){
  
    if(o.container){
      this.container = o.container.getElement('ul.lava');
      if(this.container){
        
        this.menuLeft = this.container.getLeft();
        
        this.lis = this.container.getChildren('li');
        this.current = 0;        
        this.lis.each(function(l,i){
          this.current = ( l.hasClass('active') ) ? i : this.current;
        }, this);
        
        this.tick = new Element('div', {'class':'left'});
        this.lamp = new Element('li', {'class':'back', styles:{
           height: this.lis[this.current].getSize().size.y, 
           width: this.lis[this.current].getSize().size.x,
           left: this.lis[this.current].getLeft() - this.menuLeft
        }});
        this.lamp.adopt(this.tick);
        this.container.adopt(this.lamp);
        
        this.lavafx = new Fx.Styles(this.lamp, {duration: 200, wait:false, transition: Fx.Transitions.Quad.easeInOut});
        this.lis.each(function(l,i){
          l.addEvent('mouseenter', function(){
            this.lavafx.start({ width: l.getSize().size.x, left: l.getLeft() - this.menuLeft });
          }.bind(this));
          l.addEvent('mouseleave', function(){
            this.lavafx.start({ width: this.lis[this.current].getSize().size.x, left: this.lis[this.current].getLeft() - this.menuLeft });
          }.bind(this));
        });
        
      }
    }
    
}