This faq will explain better than I can: What's the difference between dynamic and lexical (static) scoping? Between local() and my()?

As for indenting your code, nobody can force you to comment or indent your code so that it is more readable, and, you can probably get away with it as long as you're programming for yourself. But if it is for your instructor, boss, friends, coworkers or fellow perlmonks, you and your work will be appreciated more for it. :)

@a=split??,'just lose the ego and get involved!';
for(split??,'afqtw{|~'){print $a[ord($_)-97]}