if (document.images) {
    img1on = new Image();
    img1on.src = "img/uvod_01.gif";

    img2on = new Image();
    img2on.src = "img/sortiment_01.gif";
	
    img3on = new Image();
    img3on.src = "img/nabidka_01.gif";
	
    img4on = new Image();
    img4on.src = "img/tiformace_01.gif";
    
	img5on = new Image();
    img5on.src = "img/ceny_01.gif";  
	
    img6on = new Image();
    img6on.src = "img/katalog_01.gif";
	
    img7on = new Image();
    img7on.src = "img/poptavka_01.gif";
	
    img8on = new Image();
    img8on.src = "img/objednavka_01.gif";


        
    img1off = new Image();
    img1off.src = "img/uvod.gif";

    img2off = new Image();
    img2off.src = "img/sortiment.gif";
	
    img3off = new Image();
    img3off.src = "img/nabidka.gif";
	
    img4off = new Image();
    img4off.src = "img/tiformace.gif";
    
	img5off = new Image();
    img5off.src = "img/ceny.gif";  
	
    img6off = new Image();
    img6off.src = "img/katalog.gif";
	
    img7off = new Image();
    img7off.src = "img/poptavka.gif";
	
    img8off = new Image();
    img8off.src = "img/objednavka.gif";

  }
function imgOn(imgName) {
  if (document.images) { 
document[imgName].src = eval(imgName + "on.src");
}
}
function imgOff(imgName) {
   if (document.images) { 
document[imgName].src = eval(imgName + "off.src"); 
}
}