<pre>on centerWindoid  put the width of cd window into x  put the height of cd window into y  put the loc of cd window into topLeftCorner  put item 3 of the screenRect/2 into horizCenter  put item 3 of the screenRect/2 into vertiCenter  put horizCenter - (x/2) into horizLoc  put vertiCenter - (y/2) into vertiLoc  set loc of cd window to horizLoc,vertiLocend centerWindoid</pre>