Effect.ScrollTo=Class.create();Object.extend(Object.extend(Effect.ScrollTo.prototype,Effect.Base.prototype),{initialize:function(element){this.element=$(element);this.start(arguments[1]||{})},setup:function(){Position.prepare();var offsets=Position.cumulativeOffset(this.element);if(this.options.offset)offsets[1]+=this.options.offset;var max=window.innerHeight?window.height-window.innerHeight:document.body.scrollHeight-(document.documentElement.clientHeight?document.documentElement.clientHeight:document.body.clientHeight);this.scrollStart=Position.deltaY;this.delta=(offsets[1]>max?max:offsets[1])-this.scrollStart},update:function(position){Position.prepare();window.scrollTo(Position.deltaX,this.scrollStart+(position*this.delta))}});