// JavaScript Document
var pageheight;
var test1 = document.getElementById("contenttext").scrollHeight;
var test2 = document.getElementById("contenttext").offsetHeight
if (test1 > test2) { // all but Explorer Mac
	//alert("IE");
	pageheight = document.getElementById("contenttext").scrollHeight;
}
else {// Explorer Mac, Explorer 6 Strict, Mozilla and Safari
	//alert("mozilla");
	pageheight = document.getElementById("contenttext").offsetHeight;
}

var viewheight=325; //from css
if(pageheight>viewheight){
	document.getElementById("arrows").style.visibility="visible";
	document.getElementById("slider").style.visibility="visible";
}
var barheight=100;

function up(){
	go=window.setInterval("gomoveit()", 100);
	moveit = movedistancepp*(-1);
}
function down(){
	go=window.setInterval("gomoveit()", 100);
	moveit = movedistancepp;
}
function none(){
	window.clearInterval(go);
	moveit = 0;
}
function gomoveit(){
	topvalue=parseInt(document.getElementById("contenttext").style.top);
	if(moveit>0){
		if(sliderpos<maxslidepos){
			sliderpos++;
			document.getElementById("slider").style.top = sliderpos+96+"px";
			adjustcontent();
		}
	} else {
		if(sliderpos>0){
			sliderpos--;
			document.getElementById("slider").style.top = sliderpos+96+"px";
			adjustcontent();
		}
	}
}
function adjustcontent(){
	document.getElementById("contenttext").style.top = (movedistancepp*sliderpos)*-1+"px";
}

var moveit=0;
sliderheight=Math.floor(viewheight/pageheight*barheight);
document.getElementById("slider").style.height = sliderheight+"px";
//document.getElementById("imgslider").height = sliderheight;

//native scrollbar ausblenden
document.getElementById("mask").style.overflow = "hidden";
document.getElementById("contenttext").style.top = 0+"px"; //sonst ist der wert NaN

var sliderpos=0;
var lastpos=0;
var offset=0;
var maxslidepos=100-sliderheight;
var movedistancepp = Math.floor(pageheight/maxslidepos);
var drag=false;

function startDrag(e){
	if(!e){
		var e=window.event;
	}
	var targ=e.target?e.target:e.srcElement;
	if(targ.className!='slider'){
		return;
	}
    lastpos=e.clientY;
	startrange=e.clientY-sliderpos;
	endrange=e.clientY+maxslidepos-sliderpos;
    drag=true;
	document.addEventListener("mousemove", dragDiv, false);
}
function dragDiv(e){
	if(!drag){
		return;
	}
 	if(!e){
		var e=window.event;
	}
	newpos=e.clientY;
	if(newpos>=(startrange-1) && newpos<=(endrange+1)){
		difference=newpos-lastpos;
		sliderpos+=difference;
		if(sliderpos > maxslidepos){
			sliderpos=maxslidepos;
		}
		if(sliderpos < 0){
			sliderpos = 0;
		}
		document.getElementById("slider").style.top = sliderpos+96+"px";
	}
	lastpos=newpos;
	adjustcontent();
	return false;
}
function stopDrag(){
 drag=false;
}
document.addEventListener("mousedown", startDrag, false);
document.addEventListener("mouseup", stopDrag, false);