var slide_total = 0;
var slide_idx = 0;
var jsbox = null;
function showslide(idx) {
    slide_idx = idx;
    showslidenav(idx, slide_total);
    for (var i =  0; i < slide_total; i++) {
        if (i == idx) {
            jsbox.item(i).style.display = 'block';
        } else {
            jsbox.item(i).style.display = 'none';
        }
    }
}
function showslidenav(idx, total) {
    var nav = '';
    for (var i = 0; i < total; i++) {
        nav += '<a href="javascript:;" onmouseover="showslide(' + i + ')"' + (idx == i ? ' class="sel"' : '') + '></a>';
    }
    document.getElementById('slide_nav').innerHTML = nav;
}
function startslide() {
    jsbox = document.getElementById('slide_box').getElementsByTagName('div');
    slide_total = jsbox.length;
    if (slide_total == 0) return;
    slide_idx = slide_total - 1;

    var mm = setInterval(function () {
        slide_idx--;
        if (slide_idx < 0) slide_idx = slide_total - 1;
        showslide(slide_idx);
    }, 5000);
    showslide(slide_idx);
}