11  The pause button

The simplest way to pause a program is manually, by clicking the pause button in the top right corner of the window. While the program is paused, you can run other scripts by clicking on them, show variables on stage with the checkbox next to the variable in the Variables palette or with the show variable block, and do all the other things you can generally do, including modifying the paused scripts by adding or removing blocks. The button changes shape to and clicking it again resumes the paused scripts.