/[^\@aminos]/
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Update: Here is the node, as it was when I replied to it:

Hi Monks,
Im getting this error when running my script and i donīt know why

Unmatched [ in regex; marked by <-- HERE in m/[ <-- HERE ^]/ <br/>
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this is the fragment of the code where the error occurs

if( "$substr1$substr2" =~ /[^@aminos]/ )
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any ideas?