function ref_Hover(id_cko,cls_nm,img_name,img_src) {
        var element = document.getElementById(id_cko);
        element.className = cls_nm;
		document.images[img_name].src = img_src;		
      }
      
      function ref_NoHover(id_cko,cls_nm,img_name,img_src) {
        var element = document.getElementById(id_cko);
        element.className = cls_nm;
		document.images[img_name].src = img_src;
      }
      function preloadImages(urls) {
        var img = new Array();
        for (var i=0; i<urls.length; i++) {
          img[img.length] = new Image();
          img[img.length - 1].src = urls[i];
        }
      }
      function img_preload() {
        var pictures = new Array(
          "http://www.artfocus.cz/images/ref_1r-aktiv.gif",		  
          "http://www.artfocus.cz/images/ref_2r-aktiv.gif",
          "http://www.artfocus.cz/images/h-menu-sklo-l.jpg",		  
          "http://www.artfocus.cz/images/h-menu-sklo.gif",		  
		  "http://www.artfocus.cz/images/l_menu-akt-tlac1.gif",
		  "http://www.artfocus.cz/images/l_menu-akt-tlac2.gif",
		  "http://www.artfocus.cz/images/kontakt_form_tlac_akt.jpg",
		  "http://www.artfocus.cz/images/kontakt_form_text_akt.jpg",
		  "http://www.artfocus.cz/images/reference-obr-podklad-aktiv.gif",
		  "http://www.artfocus.cz/images/podklad-aktiv.gif",
          "");
        preloadImages(pictures);        
      }	  

function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImagesArray(array) {
	if (preloadFlag == true) {
		var d = document; var img;
		for (var i=0; i<array.length; i+=2) {
			img = null; var n = array[i];
			if (d.images) {img = d.images[n];}
			if (!img && d.getElementById) {img = d.getElementById(n);}
			if (img) {img.src = array[i+1];}
		}
	}
}

function changeImages() {
	changeImagesArray(changeImages.arguments);
}