Checkbox “Use Website” doesn’t work after adding new website

I am learning “Set up multiple views in the Admin”

1. I added a new website+store+view
2. then opened store > system > configuration > general > web and tried to change store url. But checkbox doesn’t active.

I select any store, view all the same. Now I cant’t change any setting of the new and old views.

In setup guide it is “Step 5: Change the website base URL”