Regression, Demonstrated

Instructions:
These instructions, like the Demo, are not yet complete.

To add points to the scatterplot, just click within the boundaries of the plot. (This works when the "Add Point" radio button is checked, the default on startup.)
To move a point, check the "Move Point" radio button and then click on (or near) the point you wish to move and drag it to the location you wish. (Note that the statistics and any displayed regression lines change as you drag the point.)
To erase a point, check the "Erase Point" checkbox and then click on (or near) the point you wish to erase.
The regression line, residuals and display of the point of means can be turned on and off with the various buttons.
You can also clear the entire scatterplot.
The plot can be "flipped" by swapping the X and Y coordinates.

Comments, constructive criticism and ideas (especially ideas!) are welcomed. Please e-mail me at srein@calpoly.edu with any thoughts.