Cannot move reference plane to cuboid's inner

Hi,

A video (http://www.youtube.com/watch?v=sAL_AExRdb8) on youtube showed how to move the reference plane to the middle of a cuboid.

I tried to follow the steps, but immediately found that I was not able to change "offset distance" to negative values so I cannot move the plane to middle of the cuboid. A closer look also shows that the content of the "plane" panel in my machine and the video are different:

1. In my machine I am asked so select 1st, 2nd and 3rd reference, and the constraints are {parallel, perpendicular, coincident, at angle, offset distance}.

2. In the video there is no 1st, 2nd or 3rd reference; the constraints are {Through lines/points, Paralle plane at point}.

Could someone tell me how can I change the panel plane to as in the video?

Qi