wjs = {
  rootWindow: function(){
    v_parent = self;
    while( v_parent != v_parent.parent ){
      v_parent = v_parent.parent;
    }
    return v_parent;
  },

  preloadImages: function(images){
    if( typeof(images)=='undefined' ) return;

    var imagenes = images.split(",");
    var i;
    var lista_imagenes = new Array();
    for(i in imagenes){
      lista_imagenes[i] = new Image();
      lista_imagenes[i].src = imagenes[i];
    }
  },

  attachEventListener:function(obj,event,func){
    if( window.addEventListener ){
      if( event == 'onload' ) event = 'load';
      window.addEventListener(event,func,false);
    }
    else {
      window.attachEvent(event, func);
    }
  },

  getScrollXY:function(){
    var scrOfX = 0, scrOfY = 0;
    if( typeof( window.pageYOffset ) == 'number' ) {
      //Netscape compliant
      scrOfY = window.pageYOffset;
      scrOfX = window.pageXOffset;
    } else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
      //DOM compliant
      scrOfY = document.body.scrollTop;
      scrOfX = document.body.scrollLeft;
    } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
      //IE6 standards compliant mode
      scrOfY = document.documentElement.scrollTop;
      scrOfX = document.documentElement.scrollLeft;
    }
    return [ scrOfX, scrOfY ];
  },

  getViewPortSize:function(){
    var size = [0, 0];

    if (typeof window.innerWidth != 'undefined')
    {
     size = [
         window.innerWidth,
         window.innerHeight
     ];
    }
    else if (typeof document.documentElement != 'undefined'
       && typeof document.documentElement.clientWidth !=
       'undefined' && document.documentElement.clientWidth != 0)
    {
     size = [
         document.documentElement.clientWidth,
         document.documentElement.clientHeight
     ];
    }
    else
    {
     size = [
         document.getElementsByTagName('body')[0].clientWidth,
         document.getElementsByTagName('body')[0].clientHeight
     ];
    }

    return size;
  },

  getBodySize:function(){
    var pageWidth = document.body.clientWidth;
    var pageHeight = document.body.clientHeight;
    //alert ("pageWidth=" + pageWidth + " pageHeight=" + pageHeight);
    return [pageWidth,pageHeight];
  },

  setBodySize:function(size){
    document.body.clientWidth = size[0];
    document.body.clientHeight = size[1];
  }
}