Datatable themes is not working

Flexigrid theme is working fine. when I try to use datatables theme then I found data but not in seeing mode. I need to block all the page then I can see.

my controller is:

function users_management()
{
        $crud = new grocery_CRUD();

        $crud->set_theme('datatables');

        $crud->set_table('users');
        $crud->columns('email','name','designation');
       $crud->unset_view();
        $output = $crud->render();

        $this->_example_output($output);
}

when I run the code I found the following page:

[attachment=1016:2.JPG]

if I block all the page by ctrl+A then I found:

[attachment=1017:1.JPG]

likhon3k