init: function() {
    this.element = $('#' + this.elementId);
    document.getElementById("layers_list_button").onclick = function() {
        system.layersList.visibility_switch(true);
    };
    return this.element;
},

visibility_switch: function(buttonClick) {
    if (system.layersList.visibility) {
        document.getElementById("layers_list").style.display = "none";
        document.getElementById("layers_list").style.visibility = "hidden";
        $("#layers_list_button").removeClass('open');
        system.layersList.visibility = false;
    } else {
        document.getElementById("layers_list").style.display = "block";
        document.getElementById("layers_list").style.visibility = "visible";
        $("#layers_list_button").addClass('open');
        system.layersList.visibility = true;
    }
},