You need to use the pipe symbol (|) within the regular expression for alternation (OR) matching - See perlman:perlre for details.

if ($form{'webcam'} =~ /http|www/i)
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You'll also note that I have added the i option to the match to perform case-insensitive matching - This allows your regular expression to match these terms within your hash, irrespective of the string case. Again, read about this in perlman:perlre.