/**
 * @author julien
 */
TopOfPage={
	_isVisible:false,
	init:function() {
		Event.observe(window,"scroll",this._scroll.bind(this));
		$$(".block-scrolltop")[0].observe("click",function(){
			new Effect.ScrollTo($$(".page")[0]);
		});
		this._scroll();
	},
	_scroll:function() {
		if (document.viewport.getScrollOffsets()[1]>0.5*document.viewport.getHeight()) {
			if (this._isVisible==false) {
				new Effect.Appear($$(".block-scrolltop")[0],{duration:0.5,queue:"end"});
				this._isVisible=true;
			}
		} else {
			if (this._isVisible==true) {
				this._isVisible=false;
				new Effect.Fade($$(".block-scrolltop")[0],{duration:0.5,queue:"end"});
			}
		}
	}
}

Event.observe(window, 'load', function() {
	TopOfPage.init();
});