function changePicOn(picNum) {
  document.getElementById("img_" + picNum).src = "images/menu/" + picNum + "_on.gif";
}

function changePicOut(picNum) {
  document.getElementById("img_" + picNum).src = "images/menu/" + picNum + "_out.gif";
}

function setLinkVisible() {
  document.getElementById("link").style.visibility = "visible";
}

function setLinkInvisible() {
  document.getElementById("link").style.visibility = "hidden";
}

function setQRVisible() {
  document.getElementById("qr").src = "http://www.activead.hu/qr/qr_img.php?d=" + document.getElementById("qrlink").value;
  document.getElementById("qrimage").style.visibility = "visible";
}

function setQRInvisible() {
  document.getElementById("qrimage").style.visibility = "hidden";
}

function emailCorrector() {
    var tags = document.body.getElementsByTagName ("*");
    for( i = 0; i < tags.length; i++ ) {
        v = tags[i];
        while (v.innerHTML.indexOf("##kukac##") != -1 ) {
            v.innerHTML = v.innerHTML.replace( /##kukac##/g, String.fromCharCode(64) );
        }
    }
}