DeleteButtonBehavior = Behavior.create({
  initialize: function() {
    this.anchor = this.element.down("a");
    if (this.anchor) this.anchor.style.visibility = "hidden";
  },
  
  onmouseover: function(event) {
    if (this.anchor) this.anchor.style.visibility = "visible";
  },
  
  onmouseout: function(event) {
    if (this.anchor) this.anchor.style.visibility = "hidden";
  }
});