I have noticed that, the webmin API doesnt support the use of strict and warning. Because any time I tried using them, I get so many "Global ...." errors which are related to the API. Why isn't the API using strict?
I'm sure only the webmin developer knows why he did not use strict, however, you can still use it. Just initialize vars you intend on importing thus:
our( %in, %text, %config );
use strict; use warnings;
Older Perl did not support the 'our' pragma, but 'vars.'  So keep that in mind if you are using an older Perl.