// WARNING: this script was severely modified by http://www.waag.org .
// WARNING: all modifications for the purpose of using more than one scrollbar per page
// WARNING: ugly code, should be rewritten using objects instead of arrays
// WARNING: do not use this, use the original script from geeeet@ghtml.com
// WARNING: All my modifications are tagged with BVB, so the original author will not be blamed.

// Made by geeeet@ghtml.com
// Keep these two lines and you're free to use this code

// Known bugs :
// If ie4.5 mac, please press apple-t to remove sidebar, otherwise everything is pushed 20px to the right...

// Corrected bugs :
// 25.01.2001 - When the height of the span "content" was less than the height of the span "contentClip" a javascript error occured, function changed : move()
// 21.02.2001 - Scrolling text wasn't selectable in ie, function changed : move()
// 05.03.2001 - Ie x and y coordinates was wrong when page was scrolled, function changed : getMouse()

// 19.04.2001 - Finally able to remove browser-scrollbar if content is longer than the browser is high:
// Just put this in the style-tag right before the end head-tag:
// body {margin-left:0; margin-right:0; margin-top:0; margin-bottom:0; width:100%;height:100%;overflow:hidden}

// And now... go to the bottom of the page...

// Browser detection
var dom = document.getElementById ? true:false;
var nn4 = document.layers ? true:false;
var ie4 = document.all ? true:false;

var mouseY; // Mouse Y position onclick
var mouseX; // Mouse X position onclick

var clickUp = false; // If click on up-arrow
var clickDown = false; // If click on down-arrow
var clickDrag = false; // If click on scrollbar
var clickAbove = false; // If click above scrollbar
var clickBelow = false; // If click below scrollbar

var timer = setTimeout("",500); // Repeat variable
var upL; // Up-arrow X
var upT; // Up-arrow Y
var downL; // Down-arrow X
var downT; // Down-arrow Y
var dragL; // Scrollbar X
var dragT; // Scrollbar Y
var rulerL; // Ruler X
var rulerT; // Ruler Y
var contentT; // Content layer Y;
var contentH; // Content height
var contentClipH; // Content clip height
var scrollLength; // Number of pixels scrollbar should move
var startY; // Keeps track of offset between mouse and span

// BVB
var nr; // which scroller we use

function getScrollerNr(e){
	// BVB i am not proud of this code but it works...
    if(ie4){
    	srcElm = event.srcElement
	}
    else if(nn4 || dom){
		srcElm = e.target
   	}
	if (dom || ie4){
		if (srcElm.tagName != "SPAN"){
			// BVB we've hit an up/down image, so take the parent which will be the span we need
			if (dom){
				id = srcElm.parentNode.id
			}
			else{
				id = srcElm.parentElement.id
			}
		}
		else{
			// BVB we've hit the span: this has to be the scrollbar
			id = srcElm.id
		}
		return id.substring(id.length-1,id.length)
	}
	else if(nn4){
		// BVB nn4: alway hit an image, always use the name of the image
		return srcElm.name
	}
} // end BVB


// Mousedown
function down(e){
	if((document.layers && e.which!=1) || (document.all && event.button!=1)) return true; // Enables the right mousebutton
	// BVB dit kan netter..., this occurs when somebody klicked somewhere else
	nr = getScrollerNr(e);
	// AO Altijd een waarde retour voor NN4.0
	if ((nr == '') || (nr == null)) return(0);
	// end BVB
	getMouse(e);
	startY = (mouseY - scrollers[nr]["dragT"]);
	
	// If click on up-arrow
	if(mouseX >= scrollers[nr]["upL"] && (mouseX <= (scrollers[nr]["upL"] + scrollers[nr]["upW"])) && mouseY >= scrollers[nr]["upT"] && (mouseY <= (scrollers[nr]["upT"] + scrollers[nr]["upH"]))){
		clickUp = true;
		return scrollUp();
	}	
	// Else if click on down-arrow
	else if(mouseX >= scrollers[nr]["downL"] && (mouseX <= (scrollers[nr]["downL"] + scrollers[nr]["downW"])) && mouseY >= scrollers[nr]["downT"] && (mouseY <= (scrollers[nr]["downT"] + scrollers[nr]["downH"]))){
		clickDown = true;
		return scrollDown();
	}
	// Else if click on scrollbar
	else if(mouseX >= scrollers[nr]["dragL"] && (mouseX <= (scrollers[nr]["dragL"] + scrollers[nr]["dragW"])) && mouseY >= scrollers[nr]["dragT"] && (mouseY <= (scrollers[nr]["dragT"] + scrollers[nr]["dragH"]))){
		clickDrag = true;
		return false;
	}
	else if(mouseX >= scrollers[nr]["dragL"] && (mouseX <= (scrollers[nr]["dragL"] + scrollers[nr]["dragW"])) && mouseY >= scrollers[nr]["rulerT"] && (mouseY <= (scrollers[nr]["rulerT"] + scrollers[nr]["scrollH"]))){
		// If click above drag
		if(mouseY < scrollers[nr]["dragT"]){
			clickAbove = true;
			clickUp = true;
			return scrollUp();
		}
		// Else click below drag
		else{
			clickBelow = true;
			clickDown = true;
			return scrollDown();
		}
	}
	// If no scrolling is to take place
	else{
		return true;
	}
}

// Drag function
function move(e){
	// BVB all statements modified for multiple scrollbars
	if(clickDrag && scrollers[nr]["contentH"] > scrollers[nr]["contentClipH"]){
		getMouse(e);
		scrollers[nr]["dragT"] = (mouseY - startY);
		
		if(scrollers[nr]["dragT"] < (scrollers[nr]["rulerT"]))
			scrollers[nr]["dragT"] = scrollers[nr]["rulerT"];		
		if(scrollers[nr]["dragT"] > (scrollers[nr]["rulerT"] + scrollers[nr]["scrollH"] - scrollers[nr]["dragH"]))
			scrollers[nr]["dragT"] = (scrollers[nr]["rulerT"] + scrollers[nr]["scrollH"] - scrollers[nr]["dragH"]);
		
		scrollers[nr]["contentT"] = ((scrollers[nr]["dragT"] - scrollers[nr]["rulerT"])*(1/scrollers[nr]["scrollLength"]));
		scrollers[nr]["contentT"] = eval('-' + scrollers[nr]["contentT"]);

		moveTo();
		
		// So ie-pc doesn't select gifs
		if(ie4)
			return false;
	}
}

function up(){
	clearTimeout(timer);
	// Resetting variables
	clickUp = false;
	clickDown = false;
	clickDrag = false;
	clickAbove = false;
	clickBelow = false;
	return true;
}

// Reads content layer top
function getT(){
	// BVB all statements modified for multiple scrollbars
    if(ie4)
    	scrollers[nr]["contentT"] = eval('document.all.content' + nr + '.style.pixelTop');
    else if(nn4)
        scrollers[nr]["contentT"] = eval('document.contentClip' + nr + '.document.content' + nr + '.top');
    else if(dom){
		elm = "content" + nr
        scrollers[nr]["contentT"] =  parseInt(document.getElementById(elm).style.top);
	}	
}

// Reads mouse X and Y coordinates
function getMouse(e){
	if(ie4){
		mouseY = event.clientY + document.body.scrollTop;
		mouseX = event.clientX + document.body.scrollLeft;
	}
	else if(nn4 || dom){
		mouseY = e.pageY;
		mouseX = e.pageX;
	}
}

// Moves the layer
function moveTo(){
		// BVB all statements modified for multiple scrollbars	
        if(ie4){
				obj = eval('document.all.content' + nr )
                obj.style.top = scrollers[nr]["contentT"];
				obj = eval('document.all.ruler' + nr )
                obj.style.top = scrollers[nr]["dragT"];
				obj = eval('document.all.drag' + nr )				
                obj.style.top = scrollers[nr]["dragT"];
        }
        else if(nn4){
				obj = eval('document.contentClip' + nr + '.document.content' + nr );
                obj.top = scrollers[nr]["contentT"];
				obj = eval('document.ruler' + nr );
                obj.top = scrollers[nr]["dragT"];
				obj = eval('document.drag' + nr );				
                obj.top = scrollers[nr]["dragT"];
        }
        else if(dom){
				elm = "content" + nr;
                document.getElementById(elm).style.top = scrollers[nr]["contentT"] + "px";
				elm = "drag" + nr;
                document.getElementById(elm).style.top = scrollers[nr]["dragT"] + "px";
				elm = "ruler" + nr;
                document.getElementById(elm).style.top = scrollers[nr]["dragT"] + "px";
        }
}

// Scrolls up
function scrollUp(){
	// BVB all statements modified for multiple scrollbars
	getT();
	
	if(clickAbove){
		if(scrollers[nr]["dragT"] <= (mouseY-(scrollers[nr]["dragH"]/2)))
			return up();
	}
	
	if(clickUp){
		if(scrollers[nr]["contentT"] < 0){		
			scrollers[nr]["dragT"] = scrollers[nr]["dragT"] - (speed*scrollers[nr]["scrollLength"]);
			
			if(scrollers[nr]["dragT"] < (scrollers[nr]["rulerT"]))
				scrollers[nr]["dragT"] = scrollers[nr]["rulerT"];
				
			scrollers[nr]["contentT"] = scrollers[nr]["contentT"] + speed;
			if(scrollers[nr]["contentT"] > 0)
				scrollers[nr]["contentT"] = 0;
			
			moveTo();
			timer = setTimeout("scrollUp()",25);
		}
	}
	return false;
}

// Scrolls down
function scrollDown(){
	// BVB all statements modified for multiple scrollbars
	getT();
	if(clickBelow){
		if(scrollers[nr]["dragT"] >= (mouseY-(scrollers[nr]["dragH"]/2)))
			return up();
	}
	if(clickDown){
		if(scrollers[nr]["contentT"] > -(scrollers[nr]["contentH"] - scrollers[nr]["contentClipH"])){			
			scrollers[nr]["dragT"] = scrollers[nr]["dragT"] + (speed*scrollers[nr]["scrollLength"]);
			if(scrollers[nr]["dragT"] > (scrollers[nr]["rulerT"] + scrollers[nr]["scrollH"] - scrollers[nr]["dragH"]))
				scrollers[nr]["dragT"] = (scrollers[nr]["rulerT"] + scrollers[nr]["scrollH"] - scrollers[nr]["dragH"]);
			
			scrollers[nr]["contentT"] = scrollers[nr]["contentT"] - speed;
			if(scrollers[nr]["contentT"] < -(scrollers[nr]["contentH"] - scrollers[nr]["contentClipH"]))
				scrollers[nr]["contentT"] = -(scrollers[nr]["contentH"] - scrollers[nr]["contentClipH"]);
			
			moveTo();
			timer = setTimeout("scrollDown()",25);
		}
	}
	return false;
}

// reloads page to position the layers again
function reloadPage(){
	location.reload();
}

// BVB hide scrollbars when content fits in window
function hideScroll(which){
	if(ie4){
		Obj = eval("document.all.up" + which + ".style")
		Obj.visibility = "hidden"
	 	Obj = eval("document.all.down" + which + ".style")
		Obj.visibility = "hidden"		
	 	Obj = eval("document.all.drag" + which + ".style")	 	 
		Obj.visibility = "hidden"		
	}
	else if(nn4){
		Obj = eval("document.up" + which )
		Obj.visibility = false
		Obj = eval("document.down" + which )
		Obj.visibility = false
		Obj = eval("document.drag" + which )
		Obj.visibility = false
	}
	else if(dom){
		elm = "up" + which
		document.getElementById(elm).style.visibility = "hidden";
		elm = "down" + which
		document.getElementById(elm).style.visibility = "hidden";
		elm = "drag" + which				
		document.getElementById(elm).style.visibility = "hidden";
	}
}
// end BVB 

// Preload
function eventLoader(){
	// BVB all statements modified for multiple scrollbars
	for (i=0; i < number_of_scrollers; i++){
		if(ie4){
			// Up-arrow X and Y variables
	        Obj = eval("document.all.up" + i + ".style")
			scrollers[i]["upL"] = Obj.pixelLeft;
	        scrollers[i]["upT"] = Obj.pixelTop;           
	        // Down-arrow X and Y variables
	        Obj = eval("document.all.down" + i + ".style")					
	        scrollers[i]["downL"] = Obj.pixelLeft;
	        scrollers[i]["downT"] = Obj.pixelTop;
	        // Scrollbar X and Y variables
	        Obj = eval("document.all.drag" + i + ".style")										
			scrollers[i]["dragL"] = Obj.pixelLeft;
	        scrollers[i]["dragT"] = Obj.pixelTop;               
	        // Ruler Y variable
	        scrollers[i]["rulerT"] = eval("document.all.ruler" + i + ".style.pixelTop")
	        // Height of content layer and clip layer
			r = eval("document.all.content" + i + ".scrollHeight");
	        scrollers[i]["contentH"] = parseInt(r);
			r = eval("document.all.contentClip" + i + ".style.height");
	        scrollers[i]["contentClipH"] = parseInt(r);
			// content top
			scrollers[i]["contentT"] = eval('document.all.content' + i + '.style.pixelTop');
		}
		else if(nn4){
		    // Up-arrow X and Y variables
			Obj = eval("document.up" + i )
			scrollers[i]["upL"] = Obj.left;
	        scrollers[i]["upT"] = Obj.top;
	        // Down-arrow X and Y variables
	        Obj = eval("document.down" + i )					
	        scrollers[i]["downL"] = Obj.left;
	        scrollers[i]["downT"] = Obj.top;
	        // Scrollbar X and Y variables
	        Obj = eval("document.drag" + i )										
	        scrollers[i]["dragL"] = Obj.left;
	        scrollers[i]["dragT"] = Obj.top;
	        // Ruler Y variable
	        scrollers[i]["rulerT"] = eval("document.ruler" + i + ".top")
	        // Height of content layer and clip layer
	        scrollers[i]["contentH"] = eval("document.contentClip" + i + ".document.content" + i + ".clip.bottom")
	        scrollers[i]["contentClipH"] = eval("document.contentClip" + i + ".clip.bottom")
			// content top
			scrollers[i]["contentT"] = eval('document.contentClip' + i + '.document.content' + i + '.top');
			//debug("done document.up" + i)
		}
		else if(dom){
		    // Up-arrow X and Y variables
			elm = "up" + i
			scrollers[i]["upL"] = parseInt(document.getElementById(elm).style.left);
	        scrollers[i]["upT"] = parseInt(document.getElementById(elm).style.top);
	        // Down-arrow X and Y variables
			elm = "down" + i
			scrollers[i]["downL"] = parseInt(document.getElementById(elm).style.left);
	        scrollers[i]["downT"] = parseInt(document.getElementById(elm).style.top);
	        // Scrollbar X and Y variables
			elm = "drag" + i
			scrollers[i]["dragL"] = parseInt(document.getElementById(elm).style.left);
	        scrollers[i]["dragT"] = parseInt(document.getElementById(elm).style.top);
	        // Ruler Y variable
			elm = "ruler" + i					
            scrollers[i]["rulerT"] = parseInt(document.getElementById(elm).style.top);
	        // Height of content layer and clip layer
	        elm = "content" + i
    	    scrollers[i]["contentH"] = document.getElementById(elm).offsetHeight;
        	document.getElementById(elm).style.top = 0 + "px";
			//document.getElementById(elm).style.font-size = 0 + "px";
    	    scrollers[i]["contentT"] =  parseInt(document.getElementById(elm).style.top);
			elm = "contentClip" + i
	        scrollers[i]["contentClipH"] = document.getElementById(elm).offsetHeight;
			// eventually hide bars when there is nothing to scroll
		}
		// Number of pixels scrollbar should move
    	scrollers[i]["scrollLength"] = ((scrollers[i]["scrollH"]-scrollers[i]["dragH"])/(scrollers[i]["contentH"]-scrollers[i]["contentClipH"]));
		// BVB hide scrollers when content does fit
		if(scrollers[i]["contentT"] < -(scrollers[i]["contentH"] - scrollers[i]["contentClipH"])){			
			hideScroll(i);
		}
	}	
	// Initializes event capturing
	if(nn4){
		document.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP);
		window.onresize = reloadPage;
	}
	document.onmousedown = down;
	document.onmousemove = move;
	document.onmouseup = up;
}