: on declaring variables not working

So I am just trying a bit of UnityScript, and as soon as I began there was an issue. I tried to write

var HipPose : Vector3;

and the colon in the middle was instantly rejected and cited as an error. What did I do wrong?

Are you using a javascript file
because there is a difference.

C#:

Vector3 HipPose;

Javascript:

var HipPose : Vector3;