document.getElementById("logout").addEventListener("click", function(event){
    $.ajax({
        url: "http://localhost:8080/logout",
        type:"POST",
        data: "{}",
        contentType:"application/json; charset=utf-8",
        dataType: 'text',
        success: function(succ){
            alert( "Logout successful.");
            window.location = "/login?logoutSuccessful";
        },
        error: function(err) {
            alert(err);
        }
    });
});