function showPopUp(head, text) {
    var popUp = document.getElementById("popUp");
    var popUp_head = document.getElementById("popUp_head");
    var popUp_text = document.getElementById("popUp_text");
    popUp_head.innerHTML = head;
    popUp_text.innerHTML = text;
    popUp.style.display = "block";
}

function hidePopUp() {
    var popUp = document.getElementById("popUp");
    popUp.style.display = "none";
}