var popupStatus = 0;

function loadPopup() {
    if (popupStatus == 0) {
        $("#backgroundPopup").css({
            "opacity": "0.7"
        });
        $("#backgroundPopup").fadeIn("slow");
        $("#popupLogin").fadeIn("slow");
        popupStatus = 1;
    }
}

function disablePopup() {
    if (popupStatus == 1) {
        $("#backgroundPopup").fadeOut("slow");
        $("#popupLogin").fadeOut("slow");
        popupStatus = 0;
    }
}

function centerPopup() {
    var windowWidth = document.documentElement.clientWidth;
    var windowHeight = document.documentElement.clientHeight;
    var popupHeight = $("#popupLogin").height();
    var popupWidth = $("#popupLogin").width();

    $("#popupLogin").css({
        "position": "absolute",
        "top": windowHeight / 2 - popupHeight / 2,
        "left": windowWidth / 2 - popupWidth / 2
    });
}

$(document).ready(function() {
    $("#loginLink").click(function() {
        centerPopup();
        loadPopup();
    });

    $("#popupLoginClose").click(function() {
        disablePopup();
    });

    $("#backgroundPopup").click(function() {
        disablePopup();
    });
    
});