function openAlertWindow(sText) {
    
    myP = document.getElementById("parag");
    myP.innerHTML = sText;
    
    var cover = document.getElementById("cover");
    cover.style.display = "block";

    cover.style.width = parseInt(document.body.clientWidth)+"px";
    cover.style.height = parseInt(document.body.clientHeight)+"px";

    var hidden = document.getElementById("alert");
    hidden.style.display = "block";

    hidden.style.left = parseInt(((document.documentElement.clientWidth/2) - (hidden.clientWidth/2)) + document.documentElement.scrollLeft)+"px";
    hidden.style.top = parseInt(((document.documentElement.clientHeight/2) - (hidden.clientHeight)) + document.documentElement.scrollTop)+"px";
}