// configuration variables gestione delllo scroll
var slow_speed = 3;
var fast_speed = 15;
var top_position_scroll = 0;
var bottom_position_scroll = 225;

// no need to touch below this line
var px = "px";
var scroll_timer = null;

function contentSetup( id, top )
{
    content = document.getElementById( id ).style;
    content.htm = document.getElementById( id );
    content.top = top + px;
}

function scrollManager( action )
{
    var args = scrollManager.arguments;
    switch ( args[ 0 ] )
    {
	case "scroll_page":
    	content_height = content.htm.offsetHeight;
    	switch ( args[ 1 ] )
    	{
    	case "up_slow":
		clearInterval( scroll_timer );
		scroll_timer = setInterval( "if(parseInt(content.top)>-(content_height-bottom_position_scroll)){content.top=(parseInt(content.top)-slow_speed+px);}else{clearInterval(scroll_timer);}", 40 );
		break;
    	case "up_fast":
		clearInterval( scroll_timer );
		scroll_timer = setInterval( "if(parseInt(content.top)>-(content_height-bottom_position_scroll)){content.top=(parseInt(content.top)-fast_speed+px);}else{clearInterval(scroll_timer);}", 20 );
		break;
    	case "dn_slow":
		clearInterval( scroll_timer );
		scroll_timer = setInterval( "if(parseInt(content.top)<top_position_scroll){content.top=(parseInt(content.top)+slow_speed+px);}else{clearInterval(scroll_timer);}", 40 );
		break;
    	case "dn_fast":
		clearInterval( scroll_timer );
		scroll_timer = setInterval( "if(parseInt(content.top)<top_position_scroll){content.top=(parseInt(content.top)+fast_speed+px)}else{clearInterval(scroll_timer);}", 20 );
		break;
    	case "all_stop":
		clearInterval( scroll_timer );
		break;
		case "return_top":
		content.top = 0+px; 
		break;
    	}
    }
}
<!--
function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->