#!/usr/local/bin/perl -w
use CGI qw(:standard);
#my $name = undef; # is ok, but you'll get a warning if $name is blank.
my $name = param("name") || ''; # better for warn!
print "Content-type: text/html\n\n"; # Setup the header for the browser
print "value = ",$name, "\n";

##</code><code>##

print "Content-type: text/html\n\n"; # Setup the header for the browser
my $name = param("name") || '';
# Allow only numbers, letters and _
if ($name && $name !~ m/^[0-9A-Za-z_]+$/i) {
print 'Error: Bad input Format';
exit; # Stop script
}