Adding spots to an area

Granted this can be copied from a book. However, I am just becoming familiar with the concepts. And I have my own goals in mind.

You can click on the blue area and add red spots to it. The corresponding coordinates are displayed the text area above.

Alternatively, you can enter the coordinates in the text area and click on "Add spot". The spot will appear at the designated position.

Messages

You will get a message in the long text area when:
  1. You click outside of the blue region.
  2. You enter coordinates which lie outside of the blue region.
  3. You have entered the maximum number of spots (in this case, 10).
Just so you know: X ranges from 0 to 450. Y ranges from 0 to 300.

Applet goes here.