bArr = new Image();
bArr.src = "gfx/arrow_bl.gif";
bArrI = new Image();
bArrI.src = "gfx/arrow_bli.gif";

function change(nr,objekt) {
 window.document.images[nr].src = objekt.src;
} 

function show_div(n) {
 document.getElementById(n).style.visibility = "visible"; 
// document.n.style.visibility = "visible"; 

}

function hide_div(n) {
document.getElementById(n).style.visibility = "hidden";
// document.n.style.visibility = "hidden"; 
}