Lesson 1 of a beginner AutoLISP tutorial series.
Without any prior knowledge of AutoLISP you will be able to code a simple (but useful) AutoLISP program at the end of this tutorial series.
If you are at a more advanced level than these tutorials are designed for, you may still gain a useful tip, insight, or idea for your own code. Individuals with prior knowledge might want to skip to about the 3rd or 4th tutorial.