Change variable deceleration from .js to .cs ??

Hi, I’m needing to change a script from being in java-script to being in c sharp.
But i don’t know how to change this variable deceleration

js:

var projectile : Rigidbody;

what is the equivalent of this declaration in c#? i’ve tried this

c#:

private projectile : Rigidbody;

but that gives me a ‘parsing error’
so what data type is a rigid body? how do i declare one?

http://unity3d.com/support/documentation/ScriptReference/index.Writing_Scripts_in_Csharp.html

Within a class you can define a field:private Rigidbody projectile;

Note that in C# if you don’t explicitly declare the scope, it is assumed to be private (whereas in JavaScript it’s public)