Well, I really recommend using CGI.pm, as everyone else has suggested, but I believe the problem with the code is: if(ref($INPUT{$thing}) eq "ARRAY") { $INPUT{$thing} = join('^', $$INPUT{$thing}); } Specifically: join('^', $$INPUT{$thing}) You've already determined that $INPUT{$thing} is an array reference, so the proper way to de-reference it is: @$INPUT{$thing} Or (more clearly) @{ $INPUT{$thing} } So your final solution is: if(ref($INPUT{$thing}) eq "ARRAY") { $INPUT{$thing} = join('^', @{$INPUT{$thing}}); }