var ImageScroller = function(_imageScrollerParentDivID, _imageScrollerChildDivID, _imageBigDivID, _imageBigID) {
   _imageScrollerParentDivID = getElem(_imageScrollerParentDivID); 
   _imageScrollerChildDivID = getElem(_imageScrollerChildDivID);
   _imageBigDivID = getElem(_imageBigDivID);
    
   var prImagePaths = new Array(); 
   var prImageAltText = new Array(); 
   var prImageClicks = new Array(); 
   var prImageDescription = new Array(); 
   var iNumOfThumbsShown = 1; 
   var iNumOfImages; 
   
   var bAutoScroll = 0; 

   var iAutoScrollDelay = 2000; 
   var bAutoScrollDirection = 1; 

   var bAutoReverse = 1; 

   var iScrollType = 1; 

   var bEnableThumbBorder = 0; 

   var bEnableCurrentCount = 0; 

   var bEnableThumbDescription = 1; 

   var bClickOpenType = 0; 

   var iImageScrollAmount = 1;

   
   var objCounterDiv = ""; 
   var objDescriptionDiv = "imgDesc"; 
   var iSmoothSlideInterval = 3; 
   var iSmoothSlideAmount = 7; 
   var moveTimer; 
   
   this.THUMB_HEIGHT = 80; 
   this.THUMB_WIDTH = 80; 
   this.THUMB_PADDING = 4; 
   
   var CURRENT_THUMB_INDEX = 1; 
   var NEW_REVERSE_OFFSET = 0; 
   var MAX_REVERSE_OFFSET = 0; 
   var NEW_FORWARD_OFFSET = 0; 
   var IS_SCROLLING = false; 

   this.setNumOfImageToScroll = function(_NumOfImagesToScroll) {
        iImageScrollAmount = parseInt(_NumOfImagesToScroll);
   };
   this.enableThumbnailDescription = function(_descriptionDivID) {
      bEnableThumbDescription = 1; 
      objDescriptionDiv = _descriptionDivID; 
      }; 
   this.setScrollType = function(_iType) {
      if (_iType == 0) {
         iScrollType = 0; 
         }
      else {
         iScrollType = 1; 
         }
      }; 
   this.setScrollSpeed = function(_iSpeed) {
      if (_iSpeed > 0 || _iSpeed < 1000) {
         iSmoothSlideInterval = _iSpeed; 
         }
      else {
         iSmoothSlideInterval = 7; 
         }
      }; 
   this.setScrollAmount = function(_iAmount) {
      if (_iAmount > 0 || _iAmount < 1000) {
         iSmoothSlideAmount = _iAmount; 
         }
      else {
         iSmoothSlideAmount = 7; 
         }
      }; 
   this.setClickOpenType = function(_openType) {
      if (_openType == 0 || _openType == 1) {
         bClickOpenType = _openType; 
         }
      }; 
   this.enableCurrentCount = function(_counterDivID) {
      bEnableCurrentCount = 1; 
      objCounterDiv = _counterDivID; 
      }; 
   this.enableThumbBorder = function(_boolean) {
      bEnableThumbBorder = _boolean; 
      }; 
   this.setThumbsShown = function(_newNumOfThumbsShown) {
      iNumOfThumbsShown = parseInt(_newNumOfThumbsShown); 
      }; 
   this.addThumbnail = function(_thumbnailURL, _fullClickURL, _thumbnailAlt, _thumbnailDescription) {
      prImagePaths[prImagePaths.length] = _thumbnailURL; 
      prImageClicks[prImageClicks.length] = _fullClickURL; 
      prImageAltText[prImageAltText.length] = _thumbnailAlt; 
      prImageDescription[prImageDescription.length] = _thumbnailDescription; 
      }; 
   this.setThumbnailHeight = function(_newThumbHeight) {
      this.THUMB_HEIGHT = _newThumbHeight; 
      }; 
   this.getThumbnailHeight = function() {
      return this.THUMB_HEIGHT; 
      }; 
   this.setThumbnailWidth = function(_newThumbWidth) {
      this.THUMB_WIDTH = _newThumbWidth; 
      }; 
   this.getThumbnailWidth = function() {
      return this.THUMB_WIDTH; 
      }; 
   this.setThumbnailPadding = function(_newThumbPadding) {
      this.THUMB_PADDING = _newThumbPadding; 
      }; 
   this.getThumbnailPadding = function() {
      return THUMB_PADDING; 
      }; 
   this.getCurrentThumbIndex = function() {
      return CURRENT_THUMB_INDEX; 
      }; 
   this.getThumbnailCount = function() {
      return iNumOfImages; 
      }; 
   this.renderScroller = function() {
      iNumOfImages = prImagePaths.length; 
      if (iNumOfThumbsShown > iNumOfImages) {
         iNumOfThumbsShown = iNumOfImages; 
         }
      MAX_REVERSE_OFFSET = 0 - (iNumOfImages - iNumOfThumbsShown) * this.THUMB_WIDTH; 
      if (this.THUMB_PADDING > 0) {
         MAX_REVERSE_OFFSET = MAX_REVERSE_OFFSET - (iNumOfImages * this.THUMB_PADDING); 
         }
      if (bEnableThumbBorder == 1) {
         MAX_REVERSE_OFFSET = MAX_REVERSE_OFFSET - (iNumOfImages * 4); 
         }
      if (iScrollType == 0) {
         _imageScrollerParentDivID.style.width = "450px";
         _imageScrollerParentDivID.style.height = "74px"
         _imageScrollerChildDivID.style.width = (this.THUMB_WIDTH * iNumOfImages) + (iNumOfImages * (this.THUMB_PADDING * 2)) + "px";
         if (bEnableThumbBorder == 1) {
           _imageScrollerChildDivID.style.width = (parseInt(_imageScrollerChildDivID.style.width) + (iNumOfImages * 8)) + "px"; 
         }
      }


      var oHref;
      var oImage;
      
     oImage = document.createElement("img");       
     oImage.src = prImageClicks[0];
     oImage.alt = prImageAltText[0];
     oImage.id = _imageBigID;
     oImage.border = 0;
     _imageBigDivID.appendChild(oImage);
     _imageBigID = getElem(_imageBigID); 
        
      for (i = 0; i < iNumOfImages; i++) {

        oImage = document.createElement("img");
            oImage.src = prImagePaths[i];
            oImage.alt = prImageAltText[i];
            oImage.border = 1;
            oImage.width = this.THUMB_WIDTH;
            oImage.height = this.THUMB_HEIGHT;
            oImage.style.padding = this.THUMB_PADDING;
            oImage.style.marginLeft = "2px";
            oImage.onclick=(function(p, d, e) {return function(){ changeImage(p, d, e) }})(prImageClicks[i], _imageBigID, prImageDescription[i]);
          _imageScrollerChildDivID.appendChild(oImage);           
      }


      
      if (bEnableCurrentCount == 1) {
         addAnEvent(window, "load", this.updateCurrentCount); 
         }
      if (bEnableThumbDescription == 1) {
         addAnEvent(window, "load", this.updateCurrentDescription); 
         }
      };
   
   this.scrollReverse = function() {
      _origOffset = parseInt(_imageScrollerChildDivID.style.marginLeft); 
      _currentOffset = parseInt(_imageScrollerChildDivID.style.marginLeft); 
      _newOffset = _currentOffset + (this.THUMB_WIDTH * iImageScrollAmount); 
      if (this.THUMB_PADDING > 0) {
         _newOffset = _newOffset + (this.THUMB_PADDING * (2 * iImageScrollAmount)); 
         }
      if (bEnableThumbBorder == 1) {
         _newOffset = _newOffset + 4; 
         }
      if (_newOffset <= 0) {
         if(_currentOffset > (_origOffset - (this.THUMB_WIDTH * iImageScrollAmount))) {
            if (IS_SCROLLING == false) {
               NEW_REVERSE_OFFSET = _newOffset; 
               moveScrollerRight(); 
               }
            }
         }
      }; 
   this.scrollForward = function() {
      _origOffset = parseInt(_imageScrollerChildDivID.style.marginLeft); 
      _currentOffset = parseInt(_imageScrollerChildDivID.style.marginLeft); 
      _newOffset = _currentOffset - (this.THUMB_WIDTH * iImageScrollAmount); 
      if (this.THUMB_PADDING > 0) {
         _newOffset = _newOffset - ((2 * iImageScrollAmount) * this.THUMB_PADDING); 
         }
      if (bEnableThumbBorder == 1) {
         _newOffset = _newOffset - 4; 
         }
      if (IS_SCROLLING == false && _newOffset >= MAX_REVERSE_OFFSET) {
         NEW_FORWARD_OFFSET = _newOffset; 
         moveScrollerLeft(); 
         }
      }; 
      

   this.updateCurrentDescription = function() {
      getElem(objDescriptionDiv).innerHTML = prImageDescription[CURRENT_THUMB_INDEX - 1]; 
      }; 
   this.updateCurrentCount = function() {
      getElem(objCounterDiv).innerHTML = CURRENT_THUMB_INDEX + "/" + iNumOfImages; 
      }; 
   function moveScrollerRight() {
      _ElementObj = _imageScrollerChildDivID; 
      _currentOffset = parseInt(_ElementObj.style.marginLeft); 
      if (_currentOffset < NEW_REVERSE_OFFSET && (_currentOffset + iSmoothSlideAmount) <= NEW_REVERSE_OFFSET) {
         _ElementObj.style.marginLeft = _currentOffset + iSmoothSlideAmount + "px"; 
         IS_SCROLLING = true; 
         moveTimer = window.setTimeout(moveScrollerRight, iSmoothSlideInterval); 
         }
      else if (_currentOffset < NEW_REVERSE_OFFSET) {
         _ElementObj.style.marginLeft = _currentOffset + 1 + "px"; 
         IS_SCROLLING = true; 
         moveTimer = window.setTimeout(moveScrollerRight, iSmoothSlideInterval); 
         }
      else {
         IS_SCROLLING = false; 
         CURRENT_THUMB_INDEX--; 
         window.clearTimeout(moveTimer); 
         if (bEnableCurrentCount == 1) {
            getElem(objCounterDiv).innerHTML = CURRENT_THUMB_INDEX + "/" + iNumOfImages; 
            }
         }
      }; 
   function moveScrollerLeft() {
      _ElementObj = _imageScrollerChildDivID; 
      _currentOffset = parseInt(_ElementObj.style.marginLeft); 
      if (_currentOffset > NEW_FORWARD_OFFSET && (_currentOffset - iSmoothSlideAmount) >= NEW_FORWARD_OFFSET) {
         _ElementObj.style.marginLeft = _currentOffset - iSmoothSlideAmount + "px"; 
         IS_SCROLLING = true; 
         moveTimer = window.setTimeout(moveScrollerLeft, iSmoothSlideInterval); 
         }
      else if (_currentOffset > NEW_FORWARD_OFFSET) {
         _ElementObj.style.marginLeft = _currentOffset - 1 + "px"; 
         IS_SCROLLING = true; 
         moveTimer = window.setTimeout(moveScrollerLeft, iSmoothSlideInterval); 
         }
      else {
         IS_SCROLLING = false; 
         CURRENT_THUMB_INDEX++; 
         window.clearTimeout(moveTimer); 
         if (bEnableCurrentCount == 1) {
            getElem(objCounterDiv).innerHTML = CURRENT_THUMB_INDEX + "/" + iNumOfImages; 
            }
         }
      }; 
   function addAnEvent(_obj, _eventName, _functionName) {
      if (window.addEventListener) {
         _obj.addEventListener(_eventName, _functionName, false); 
         }
      else {
         _obj.attachEvent("on" + _eventName, _functionName); 
         }
      }; 
   function getElem(_elemID) {
      return document.getElementById(_elemID); 
      }; 
   };

   
   
function changeImage(imgSrc, target, desc) {
  descDiv = document.getElementById('imgDesc');
  descDiv.innerHTML = desc; 
  target.src = imgSrc;
}