function menuOut(name) {
       setImage(name, name);
}

function menuOver(name) {
       setImage(name, name + "_on");
}

function setImage(source, destination) {
       img = eval(destination);
       document.getElementById(source).src=img.src;
}

function ChangeImage(img, img_loc)
{
       document.getElementById(img).src=img_loc
}

function ChangeTar() {
  var i;
  var quant = 3;
  i = Math.floor(Math.random() * quant)+1;
  var st = "./images/tarelka"+i+".jpg";
  document.getElementById("tarelka").style.backgroundImage = "url(" + st + ")";
}