can I Use Bootstrap multiselect.css and bootstrap multiselect.js in my website i'm confuse about it. i'm not going to change the internal code
I read the license agreement supplied on the bootstrap.multiselect.js GitHub page as provided by David Stutz. According to my understanding of the license as provided, since you are not redistributing the work as a part of your own work or another project there should be no reason you can not use the work on your own site.
You may want to include this in your source as well:
/** * bootstrap-multiselect.js 1.0.0 * https://github.com/davidstutz/bootstrap-multiselect * * Copyright 2012, 2013 David Stutz * * Dual licensed under the BSD-3-Clause and the Apache License, Version 2.0. * See the README. */