var active_example = "";
var active_play_img = "";

function play_example(obj_button, play_img, pause_img, mp3_file) {
    stop_active_examples();
    active_play_img = play_img;
    
    if (active_example != obj_button) {
        add_player(mp3_file);
        document.getElementById(obj_button).src = pause_img;
        active_example = obj_button;
    }
    else {
        stop_player();
        active_example = "";
        active_play_img = "";   
    }
}

function stop_active_examples() {
    if (active_example.length > 0) {
        document.getElementById(active_example).src = active_play_img;
    }
}