Unity and Visual Studio cooperation problem

Hello everyone.

I’m working on Windows 7 64 bit. Before I was using Visual Studio 2010 and Unity3D 5.3.3. Now I’m using Visual Studio 2015 Community. When at first time I tried to create scripts in Js (in 2010) everything was working well, but after a break I noticed that there is no auto-complete for Unity’s typical names and that I am unable to see accessible fields and methods and for example pragma strict is marked as incorrect. In VS 2015 it’s the same. In Unity preferences the external script editor is set to Visual Studio 2015.

To the best of my knowledge, Visual Studio does not support JS (or UnityScript) at all. It’s meant for C#.