function PageExtender(used_height){
    var elemet_id = "page_extender";
    var elem = null;
    if(elem = document.getElementById(elemet_id)){
           
        var w, h;
        if (self.innerHeight) // all except Explorer
        {
            w = self.innerWidth;
            h = self.innerHeight;
        }
        else if ((document.documentElement != null) && (document.documentElement.clientHeight != null))
            // Explorer 6 Strict Mode
        {
            w = document.documentElement.clientWidth;
            h = document.documentElement.clientHeight;
        }
        else if (document.body) // other Explorers
        {
            w = document.body.clientWidth;
            h = document.body.clientHeight;
        }
     
      var diff = h - used_height;
      //alert(diff);
      if(diff < 0) diff = 0;
      elem.style.height = diff +"px";
      //ExtendActions();
    }
}