window.onload = Window_OnLoad;


function Window_OnLoad() {
    var movePictureLeft = document.getElementById('movePictureLeft');
    var movePictureRight = document.getElementById('movePictureRight');
    
    movePictureLeft.onclick = movePictureLeft_OnClick;
    movePictureRight.onclick = movePictureRight_OnClick;
    
    var pictures = document.getElementsByName('picture');
    for (var iPicture = 1; iPicture < pictures.length; iPicture++) {
        pictures[iPicture].className = 'oculto';
    }
}

function movePictureLeft_OnClick() {
    var pictures = document.getElementsByName('picture');
    var iPosActual = -1;
    for (var iPicture = 0; iPicture < pictures.length; iPicture++) {
        if (pictures[iPicture].className != 'oculto')
            iPosActual = iPicture;
        pictures[iPicture].className = 'oculto';
    }
    if (iPosActual > 0)
        iPosActual--;
    pictures[iPosActual].className = '';
}

function movePictureRight_OnClick() {
    var pictures = document.getElementsByName('picture');
    var iPosActual = -1;
    for (var iPicture = 0; iPicture < pictures.length; iPicture++) {
        if (pictures[iPicture].className != 'oculto')
            iPosActual = iPicture;
        pictures[iPicture].className = 'oculto';
    }
    if (iPosActual < pictures.length - 1)
        iPosActual++;
    pictures[iPosActual].className = '';
}