Coregistrations can be preformed manually using mouse interactions with the three coreg tool Tvs. Once both data volumes have been loaded, select the ``Mouse" drop-down list using a right mouse click in the Tv, and select ``zoom" using a left mouse click. Do this in all three Tvs in turn. The source image volume can then be manipulated using the mouse. With the mouse pointer over one of the Tvs, holding down the left mouse button and moving the mouse will translate the source image with respect to the target image. The source image will be displayed as a wire-frame during this process. On releasing the left mouse button, the displays in all three Tvs will be updated with the translation that has been applied. The centre mouse button will apply rotations in a similar fashion (this functionality may be achieved by holding down both the left and right mouse buttons on certain systems with two-button mice). The right mouse button applies scalings. Right click and hold, then drag to draw a rectangle. The source image volume will then be scaled to fit inside this rectangle: if the rectangle lies within the Tv, the source image volume will be scaled down; if the rectangle is bigger than the Tv, the source image volume will be scaled up.