function showBooks () {
    document.getElementById('new-books-tab').style.display = '';
    document.getElementById('new-music-tab').style.display = 'none';
    document.getElementById('new-movies-tab').style.display = 'none';
}

function showMusic () {
    document.getElementById('new-books-tab').style.display = 'none';
    document.getElementById('new-music-tab').style.display = '';
    document.getElementById('new-movies-tab').style.display = 'none';
}

function showMovies () {
    document.getElementById('new-books-tab').style.display = 'none';
    document.getElementById('new-music-tab').style.display = 'none';
    document.getElementById('new-movies-tab').style.display = '';
}

function passwordBlur() {
    if(document.getElementById("passwordMasked").value.length == 0) {
        document.getElementById("passwordMasked").style.display = "none";
        document.getElementById("passwordText").style.display = '';
    }
}

function passwordFocus() {
    document.getElementById("passwordMasked").style.display = '';
    document.getElementById("passwordText").style.display = "none";
    document.getElementById("passwordMasked").focus();
}

function usernameBlur() {
    if(document.getElementById("username").value.length == 0) {
        document.getElementById("username").value = "username";
    }
}

function usernameFocus() {
    if(document.getElementById("username").value == "username") {
        document.getElementById("username").value = "";
    }
}