I could haven't added a j query to the " application .java script

I thought this problem caused by version up . I heard before this kind of problem is often occur in a  programming .

Have to solve this problem ?

1.search on an internet whether solution has or not

Result

 I found (J query - ui -rails )out and then I added to the code  to gem file , and bundle update

But not function anymore

Ok

Now if I could not added the code to gem file which mean , I could not use drop down list

Here are drop down list of picture