window.addEvent('domready', function() {

  var site = $('okienko');
  if ( site ){
  var avalible_height = ( document.documentElement.clientHeight ) ? document.documentElement.clientHeight : window.innerHeight ; 
  if ( avalible_height < site.getSize().size.y ){
    site.setStyle('marginTop','0');
    site.setStyle('top','0');
    }

  $('slider');
	var sizes = $("scroll_content").getSize(); 
	
  if ( sizes.size.y >= sizes.scrollSize.y ){
    $('slider').remove();
    return true ;
    }

  var perStep = 5 ; 
      
  var s = ( ( sizes.scrollSize.y -  sizes.size.y  ) / perStep ).round();

	if(sizes.scrollSize.y > s){ 
		s++;
	}
	
	$('slider');
	
	var mySlide  = new Slider("track","knob",{
		steps: s,
		mode: "vertical",
		onChange: function(step){
			$("scroll_content").scrollTo(0, step * perStep );
		}
	}).set(0);

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

Element.Events.extend({
	'wheelup': {
		type: Element.Events.mousewheel.type,
		map: function(event){
			event = new Event(event);
			if (event.wheel >= 0) this.fireEvent('wheelup', event)
		}
	},
	'wheeldown': {
		type: Element.Events.mousewheel.type,
		map: function(event){
			event = new Event(event);
			if (event.wheel <= 0) this.fireEvent('wheeldown', event)
		}
	}
});


//#############################################################
//#############################################################

$('scroll_content').addEvents({
	'wheelup': function(e) {
		e = new Event(e).stop();
    var sizes = this.getSize();
    new_s = ( ( s * sizes.scroll.y ) / ( sizes.scrollSize.y -  sizes.size.y ) ).round();
    mySlide.set( new_s ) ;
    this.scrollTo(0 , this.getSize().scroll.y - perStep * 2 ) ; 
	},
	'wheeldown': function(e) {
		e = new Event(e).stop();
    var sizes = this.getSize();
    new_s = ( ( s * sizes.scroll.y ) / ( sizes.scrollSize.y -  sizes.size.y ) ).round();
    mySlide.set( new_s ) ;
    this.scrollTo(0 , this.getSize().scroll.y + perStep * 2 ) ; 
	}
});


}

});