If you use the submit command instead (either by typing "submit" on the command line or by choosing "submit" from the "Locals" menu), you must remember to clear the windows yourself (by giving the clear command on the command line of each window or choosing "Clear text" from the "Edit" menu in each window) each time before you execute a program.
Besides the possibility of becoming confused when looking at old log notes or output, you might print an output window that has a lot of old output. This wastes a lot of paper.
By clearing your windows before executing a program, you will have only the fresh log-notes and output that pertain to the program you just executed. There is an easy way to do it: the Control-E key sequence.
While your program is executing, the cursor also disappears. When it reappears, execution is finished.
The next step is to look at the contents of the Log window. Position the on-screen cusor in the log window with the mouse and press the left button to make the log window current. Then either hit Control-t or use the mouse (by placing it on the arrow at the top of the scroll bar and pressing the left mouse button) to go to the top of the Log window.
Spend a little time in this window and you will see how useful it really is. Error messages, warnings and other bits of information found here will help you correct problems in your program.