You have not given us a complete working example:

S:\Steve\Dev\PerlMonks\P-2017-08-15@0704-combobox>perl combobox0a.pl
Global symbol "$str" requires explicit package name at combobox0a.pl l
+ine 5.
Global symbol "@array" requires explicit package name at combobox0a.pl
+ line 6.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 9.
Global symbol "$arraylist" requires explicit package name at combobox0
+a.pl line 10.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 11.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 11.
Global symbol "@array" requires explicit package name at combobox0a.pl
+ line 11.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 11.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 12.
Global symbol "$arraylist" requires explicit package name at combobox0
+a.pl line 13.
Global symbol "@array" requires explicit package name at combobox0a.pl
+ line 13.
Global symbol "$arraylist" requires explicit package name at combobox0
+a.pl line 16.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 16.
Global symbol "@array" requires explicit package name at combobox0a.pl
+ line 16.
Global symbol "$id" requires explicit package name at combobox0a.pl li
+ne 16.
Execution of combobox0a.pl aborted due to compilation errors.

S:\Steve\Dev\PerlMonks\P-2017-08-15@0704-combobox>
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