Error : Unknown identifier:'iTween' Solution for Noob

If you are using Unity and after you importing Itween and when you create a new simple javascript such as 

function Start () 

{

    iTween.MoveTo(gameObject,{"y":5} );

}

If you get error 
Error : Unknown identifier:'iTween'

here is the solution to fix this

first, please notice that your folder is ITWEEN -> PLUGIN -> itween.cs

So, first level = ITWEEN

second level = PLUGIN

move your PLUGIN folder to first level

so now your folder look like this 

ITWEEN

PLUGIN -> itween.cs

so both ITWEEN folder and PLUGIN are on the same level , first level

this will work and your error will be gone

hope this help, please note i spend 2 hour for fixing this, so I will really appreciate if you can leave a comment to thank me, thanks