菜单内容在点击时不会崩溃 - Bootstrap

I am pretty new to bootstrap. I am currently working on Navbar. want to make it responsive on collapse. it works perfectly fine when i am working locally. But i see that menu bar does not close contents on click. I tried to use the CSS link and script link from CDN. also made use of the folders. But i suspect somewhere script is not loading as expected.I am pretty new to bootstrap. I am currently wo