show: function(speed,callback){
		var hidden = this.filter(":hidden");
    if(hidden.length){
		speed ?
			hidden.animate({
				height: "show", width: "show", opacity: "show"
			}, speed, callback) :
			
			hidden.each(function(){
				this.style.display = this.oldblock ? this.oldblock : "";
				if ( jQuery.css(this,"display") == "none" )
					this.style.display = "block";
			});
    }else{
      if (callback) callback();
    }
		return this;
	},

	hide: function(speed,callback){
		var visible = this.filter(":visible");
    if(visible.length){
		speed ?
			visible.animate({
				height: "hide", width: "hide", opacity: "hide"
			}, speed, callback) :
			
			visible.each(function(){
				this.oldblock = this.oldblock || jQuery.css(this,"display");
				if ( this.oldblock == "none" )
					this.oldblock = "block";
				this.style.display = "none";
			});
    }else{
      if (callback) callback();
    }
		return this;
	},

so. callback is Security.