/**
  All roll over images must be named: IMAGE_NAME_roll.EXT :
    IMAGE_NAME : same name as normal
    EXT : same ext normal.
  A little bit hardcoded in the beginning, but it's only the beginning.
*/
var ImagesContainer = new Array();

function VS_LoadRollImage(imageObject) {
  var fileExt  = VS_Util_GetFileExt(imageObject.src);
  var fileName = imageObject.src.split(fileExt)[0];


  if (ImagesContainer[fileName] )
    return;

  var rollImage = new Image();
  rollImage.src = fileName + "_over" + fileExt;

  imageObject.isSelected = false;
  rollImage.isSelected = false;

  ImagesContainer[fileName]           = imageObject.src ;
  ImagesContainer[fileName + "_over"] = rollImage;
}

function VS_RollOverImage(imageObject, roll) { 
 if (ImagesContainer) {
    if ( typeof(imageObject.isSelected) != "undefined"  && imageObject.isSelected == true)
    	return;
  	
    if (roll == true && ImagesContainer[VS_Util_GetFileName(imageObject.src, false) + "_over"]) {
  //alert(VS_Util_GetFileName(imageObject.src, false));
      imageObject.src = ImagesContainer[VS_Util_GetFileName(imageObject.src, false) + "_over"].src;
    } else if (ImagesContainer[VS_Util_GetFileName(imageObject.src, true)]) {
  //alert(VS_Util_GetFileName(imageObject.src, true) + "::" + ImagesContainer[VS_Util_GetFileName(imageObject.src, true)]);
      imageObject.src = ImagesContainer[VS_Util_GetFileName(imageObject.src, true)];  
    }
  }
}

function VS_SelectCurrent(obj) {
	obj.isSelected = true;
	obj.src =  ImagesContainer[VS_Util_GetFileName(obj.src, false)].src;
}

function VS_Util_GetFileName(file, isRollover) {
  file = file.split(VS_Util_GetFileExt(file))[0];
  if ( !isRollover )
    return file;
  else
    return file.split("_over")[0]
}

function VS_Util_GetFileExt(file) {
	if (file.indexOf(".jpg") > 0)
		return ".jpg";
	else if (file.indexOf(".jpeg") > 0)
		return ".jpeg";
	else if (file.indexOf(".gif") > 0)
		return ".gif";
}