in reply to
Re^2: connecting to ftp sites and download certain files based on file extensions
in thread connecting to ftp sites and download certain files based on file extensions
In general, when you see a message like that, Perl is telling you that you are trying to call an object method (in this case, 'cwd') on something that is not actually an object of that type. As Inigo Montoya says about Vizzini's use of the word 'inconceivable': "I do not think that word means what you think it means." Perl is saying, "I do not think that $ftp variable is really a Net::FTP class member."
The real error seems to be that your $ftp object creation didn't actually succeed -- you may want to look back at the results from the new() and login() methods to make sure that you do, in fact, have a valid, connected Net::FTP object when you call the 'cwd' method.