Like many scripting languages, there is no real way to do block comments in Perl. The proper way to do a block comment is simply to comment out each line with a # along the left side, and in fact many popular text editors such as vim and emacs facilitiate this behavior (we have a tutorial on how to do it in emacs here).
There is an easier way to make the compiler ignore a block of code if you are interested in a less visibly-obvious solution. This is great for short-term solutions but it typically should not be used for scripts others will see.
In the example above, "COMMENTS' is just a label and can be changed as long as it is consistent across begin and end.