    option.thick = option.thick || d4.thick;
    option.color = option.color || d4.color;

    // init position
    switch(option.position) {
        case 'top':
            progress.style.top = 0;
            progress.style.left = 0;
            progress.style.width = '100%';
            progress.style.height = option.thick + 'px';
            div.style.height = '100%';
        break;
        case 'bottom':
            progress.style.bottom = 0;
            progress.style.left = 0;
            progress.sty