// slide handler

var curSlide;

function initSlides (num) {
    //alert(num);
    curSlide = num;
    showCurrentSlide();
}

function showCurrentSlide () {
    hideSlide( document.getElementById( slides[0] ) );
    var sl = document.getElementById( slides[curSlide] );
    if (!sl) {
        alert("Slide not found at index: " + curSlide);
        return;
    }
    showSlide(sl);
}

function hideCurrentSlide () {
    var sl = document.getElementById( slides[curSlide] );
    if (!sl) {
        alert("Slide not found at index: " + curSlide);
        return;
    }
    hideSlide(sl);
}

function showNext () {
    if (curSlide == slides.length - 1) return;
    hideCurrentSlide();
    curSlide++;
    showCurrentSlide();
}

function showPrev () {
    if (curSlide == 0) return;
    hideCurrentSlide();
    curSlide--;
    showCurrentSlide();
}

function jumpTo (pos) {
    pos += 1;
    if (pos <= 0 || pos > slides.length) return;
    hideCurrentSlide();
    curSlide = pos - 1;
    showCurrentSlide();
}

function showSlide (sl) { sl.setAttribute( 'style', 'display:block' ); }
function hideSlide (sl) { sl.setAttribute( 'style', 'display:none'  ); }


function showMap () {
    document.getElementById('map').setAttributeNS( null, 'display', 'block' );
}