// This JavaScript Scroller code provided by http://www.ghtml.com
// "Keep these two lines and you're free to use this code"

// Scroller and Scrollbar preferrences listed here
var upH = 18; // Up-Arrow Height
var upW = 18; // Up-Arrow Width
var downH = 18; // Down-Arrow Height
var downW = 18; // Down-Arrow Width
var dragH = 50; // Scrollbar Length
var dragW = 50; // Scrollbar Width
var scrollH = 390; // Scrollbar Height
var speed = 3; // Scrolling Speed

// Browser Detections
var dom = document.getElementById ? true:false;
var nn4 = document.layers ? true:false;
var ie4 = document.all ? true:false;
var mouseY;
var mouseX;
var clickUp = false;
var clickDown = false;
var clickDrag = false;
var clickAbove = false;
var clickBelow = false;
var timer = setTimeout("",500);
var upL;
var upT;
var downL;
var downT;
var dragL;
var dragT;
var rulerL;
var rulerT;
var contentT;
var contentH;
var contentClipH;
var scrollLength;
var startY;

// MouseDown Functions
function down(e){
  if((document.layers && e.which!=1) || (document.all && event.button!=1)) return true;
  getMouse(e);
  startY = (mouseY - dragT);
  
  if(mouseX >= upL && (mouseX <= (upL + upW)) && mouseY >= upT && (mouseY <= (upT + upH))){
    clickUp = true;
    return scrollUp();
  }  

  else if(mouseX >= downL && (mouseX <= (downL + downW)) && mouseY >= downT && (mouseY <= (downT + downH))){
    clickDown = true;
    return scrollDown();
  }

  else if(mouseX >= dragL && (mouseX <= (dragL + dragW)) && mouseY >= dragT && (mouseY <= (dragT + dragH))){
    clickDrag = true;
    return false;
  }
  else if(mouseX >= dragL && (mouseX <= (dragL + dragW)) && mouseY >= rulerT && (mouseY <= (rulerT + scrollH))){

    if(mouseY < dragT){
      clickAbove = true;
      clickUp = true;
      return scrollUp();
    }

    else{
      clickBelow = true;
      clickDown = true;
      return scrollDown();
    }
  }

  else{
    return true;
  }
}

// Scrollbar Dragger Functions
function move(e){
  if(clickDrag && contentH > contentClipH){
    getMouse(e);
    dragT = (mouseY - startY);
    
    if(dragT < (rulerT))
      dragT = rulerT;    
    if(dragT > (rulerT + scrollH - dragH))
      dragT = (rulerT + scrollH - dragH);
    
    contentT = ((dragT - rulerT)*(1/scrollLength));
    contentT = eval('-' + contentT);

    moveTo();
    
    if(ie4)
      return false;
  }
}

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

function getT(){
  if(ie4)
    contentT = document.all.scroll_content.style.pixelTop;
  else if(nn4)
    contentT = document.scroll_contentClip.document.content.top;
  else if(dom)
    contentT = parseInt(document.getElementById("scroll_content").style.top);
}

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;
  }
}

function moveTo(){
  if(ie4){
    document.all.scroll_content.style.top = contentT;
    document.all.scroll_ruler.style.top = dragT;
    document.all.scroll_drag.style.top = dragT;
  }
  else if(nn4){
    document.scroll_contentClip.document.scroll_content.top = contentT;
    document.scroll_ruler.top = dragT;
    document.scroll_drag.top = dragT;
  }
  else if(dom){
    document.getElementById("scroll_content").style.top = contentT + "px";
    document.getElementById("scroll_drag").style.top = dragT + "px";
    document.getElementById("scroll_ruler").style.top = dragT + "px";
  }
}

// DIV Layer Up-Scrolling Functions
function scrollUp(){
  getT();
  
  if(clickAbove){
    if(dragT <= (mouseY-(dragH/2)))
      return up();
  }
  
  if(clickUp){
    if(contentT < 0){    
      dragT = dragT - (speed*scrollLength);
      
      if(dragT < (rulerT))
        dragT = rulerT;
        
      contentT = contentT + speed;
      if(contentT > 0)
        contentT = 0;
      
      moveTo();
      timer = setTimeout("scrollUp()",25);
    }
  }
  return false;
}

// DIV Layer Down-Scrolling Functions
function scrollDown(){
  getT();
  
  if(clickBelow){
    if(dragT >= (mouseY-(dragH/2)))
      return up();
  }

  if(clickDown){
    if(contentT > -(contentH - contentClipH)){      
      dragT = dragT + (speed*scrollLength);
      if(dragT > (rulerT + scrollH - dragH))
        dragT = (rulerT + scrollH - dragH);
      
      contentT = contentT - speed;
      if(contentT < -(contentH - contentClipH))
        contentT = -(contentH - contentClipH);
      
      moveTo();
      timer = setTimeout("scrollDown()",25);
    }
  }
  return false;
}

// Upon Reload, Repositions the DIV Layers to Default
function reloadPage(){
  location.reload();
}

// Preloading the Images
function eventLoader(){
  if(ie4){
    upL = document.all.scroll_up.style.pixelLeft;
    upT = document.all.scroll_up.style.pixelTop;    
    downL = document.all.scroll_down.style.pixelLeft;
    downT = document.all.scroll_down.style.pixelTop;
    dragL = document.all.scroll_drag.style.pixelLeft;
    dragT = document.all.scroll_drag.style.pixelTop;    
    rulerT = document.all.scroll_ruler.style.pixelTop;    
    contentH = parseInt(document.all.scroll_content.scrollHeight);
    contentClipH = parseInt(document.all.scroll_contentClip.style.height);
  }
  else if(nn4){
    upL = document.scroll_up.left;
    upT = document.scroll_up.top;    
    downL = document.scroll_down.left;
    downT = document.scroll_down.top;    
    dragL = document.scroll_drag.left;
    dragT = document.scroll_drag.top;    
    rulerT = document.scroll_ruler.top;
    contentH = document.scroll_contentClip.document.content.clip.bottom;
    contentClipH = document.scroll_contentClip.clip.bottom;
  }
  else if(dom){
    upL = parseInt(document.getElementById("scroll_up").style.left);
    upT = parseInt(document.getElementById("scroll_up").style.top);
    downL = parseInt(document.getElementById("scroll_down").style.left);
    downT = parseInt(document.getElementById("scroll_down").style.top);
    dragL = parseInt(document.getElementById("scroll_drag").style.left);
    dragT = parseInt(document.getElementById("scroll_drag").style.top);
    rulerT = parseInt(document.getElementById("scroll_ruler").style.top);
    contentH = parseInt(document.getElementById("scroll_content").offsetHeight);
    contentClipH = parseInt(document.getElementById("scroll_contentClip").offsetHeight);
    document.getElementById("scroll_content").style.top = 0 + "px";
    
  }
  scrollLength = ((scrollH-dragH)/(contentH-contentClipH));
  if(nn4){
    document.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP);
    window.onresize = reloadPage;
  }
  document.onmousedown = down;
  document.onmousemove = move;
  document.onmouseup = up;
}