/* A slightly modified version of the DHTML SCROLLBAR from http://13thparallel.com */

// We wrap all the code in an object so that it doesn't interfere with any other code
var scroller = {
  
  init:   function() {
  
  // Collect the variables
  scroller.docH = document.getElementById("wtag_content").offsetHeight;
  scroller.contH = document.getElementById("wtag_container").offsetHeight;
  scroller.scrollAreaH = document.getElementById("scrollArea").offsetHeight;
    
  // What is the effective scroll distance once the scoller's height has been taken into account
  scroller.scrollDist = Math.round(scroller.scrollAreaH-20);
    
  // Make the scroller div draggable
  if(scroller.docH > 160) {
   
  document.getElementById("scroller").style.height = "20px";
    
  // Change scroller width here
  document.getElementById("scroller").style.width = "8px";
  
  
    
  Drag.init(document.getElementById("scroller"),null,0,0,-1,scroller.scrollDist);
   
  // Add ondrag function
  document.getElementById("scroller").onDrag = function (x,y) {
  var scrollY = parseInt(document.getElementById("scroller").style.top);
  var docY = 0 - (scrollY * (scroller.docH - scroller.contH) / scroller.scrollDist);
  if (docY>0) { docY=0; document.getElementById("scroller").style.top= '0px'; } 
  document.getElementById("wtag_content").style.top = docY + "px";
  
  
  }  
  } 
  
    
    
}
}

function SetScroller() {
  var v_pos=$('wtag_content').getStyle('top').toInt();  
  
  var s_pos=scroller.scrollAreaH*(-v_pos/scroller.docH);
  
  $('scroller').setStyle('top',s_pos);
}


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

$('wtag_container').addEvent('mousewheel', function(event) {
  event.stop();
	event = new Event(event);
  var v_step=24;
  var v_pos=$('wtag_content').getStyle('top').toInt();
  
  /* Mousewheel UP */
	if (event.wheel > 0) {
    
    if (v_pos<0) {
      $('wtag_content').setStyle('top',v_pos+v_step);
    } else {
      $('wtag_content').setStyle('top',0);
    }
	} 
	/* Mousewheel DOWN*/
	else if (event.wheel < 0) {
    if (v_pos>-(scroller.docH-scroller.contH)) {
    
		  $('wtag_content').setStyle('top',v_pos-v_step);
     
    } //else { 
     // alert(scroller.docH);
    //}
	}
  SetScroller();
});



});