Once in a while I see people calling subroutines in perl like this: 

&some_sub($param);

That & character at the beginning should not be there.

Instead of repeating the explanation let me just point you to the article by Dave Cross:

Subroutines and Ampersands

The only place where you need to put & in-front of the subroutine name is when you take a refernce to it: 

my $ref = \&some_sub;