In add to pjf answer I want to point that if you want to return at least 2 lists (arrays or hashes) it's better to return references, because

return (@a,@b)
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should push @a and @b in a list, and then return this list. It is not possible to separate them.

It's better to code:

return (\@a,\@b);
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and then receive the arrays as references

($ra,$rb)=myfunc();
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See perldoc perlref for more details
I want to point also that returning a referece is faster and cheaper (in terms of CPU and memory), but better is not the best word we can use, it depends of the problem (See this node written by merlyn)

Hope this help
Hopes

Thanks to graq for the information about the typo in my code