If I'm understanding you correctly, you want to pass form values. Fine. CGI.pm has methods suitable for doing that in a much neater way than what you are attempting. The param() function is the one you want.
in reply to Variable Substitution within NameSpace
So you've got that form element. Once you've submitted, call the param() function and bind that element to a variable in the script you call in the action attribute of your form definition.
<input type="text" name="custtype" value="whatever'>
param() examines the query string submitted to by your form and pulls the values out of that. In this case $cust would hold the value 'whatever'.
my $q = CGI->new();
my $cust = $q->param('custtype');
This @ISA my cool %SIG