code: function(gotoEnd){
  		var t = now();
  
  		if ( gotoEnd || t >= this.options.duration + this.startTime ) {
  			this.now = this.end;
  			this.pos = this.state = 1;
  			this.update();
  
  			this.options.curAnim[ this.prop ] = true;
  
  			var done = true;
  			for ( var i in this.options.curAnim )
  				if ( this.options.curAnim[i] !== true )
  					done = false;
  
  			if ( done ) {
  				if ( this.options.display != null ) {
  					// Reset the overflow
  					this.elem.style.overflow = this.options.overflow;
  
  					// Reset the display
  					this.elem.style.display = this.options.display;
  					if ( jQuery.css(this.elem, "display") == "none" )
  						this.elem.style.display = "block";
  				}
  
  				// Hide the element if the "hide" operation was done
  				if ( this.options.hide )
  					jQuery(this.elem).hide();
  
  				// Reset the properties, if the item has been hidden or shown
  				if ( this.options.hide || this.options.show )
  					for ( var p in this.options.curAnim )
  						jQuery.attr(this.elem.style, p, this.options.orig[p]);
  					
  				// Execute the complete function
  				this.options.complete.call( this.elem );
  			}
  
  			return false;
  		} else {
  			var n = t - this.startTime;
  			this.state = n / this.options.duration;
  
  			// Perform the easing function, defaults to swing
  			this.pos = jQuery.easing[this.options.easing || (jQuery.easing.swing ? "swing" : "linear")](this.state, n, 0, 1, this.options.duration);
  			this.now = this.start + ((this.end - this.start) * this.pos);
  
  			// Perform the next step of the animation
  			this.update();
  		}
  
  		return true;
  	}
docs: Each step of an animation