So a co-worker of mine asked me to write a script/program to rename 150 files!

I got the gist of it done... however, when I try to put 3 variables together to form a part of a new file name using the following syntax, I can't get it to work...

my $final = "$a1" . "" . "$a2" . "m" . "$d3" . "e";

so if $a1 = peter, $a2 = paul, and $d3 = mary, I want $final to be "peterpaulmmarye". Concatenating is done using "." operator I thought... however, with or without quotes around the variables, I keep getting

Global symbol "$a2" requires explicit package name at rename.pl line 33.

error messages... Any help would be appreciated...