function menu_item(menu_name){
    this.menu_name=menu_name;

    this.create = function(){
        $('body').html("<div id=" + menu_name + " />");
    };

    $('#' + menu_name).on('click',function(){
        alert (menu_name);
    });
}

menu_item("test");
menu_item.create();

function MenuItem(name){
    this.menu_name = name;

    this.create = function() {
        var el = $("<div id=" + menu_name + " />");
        el.on('click',function(){
            alert (menu_name);
        });
        $('body').append(el);
    };
}

var menu = new MenuItem("test");
menu.create();