title: Error message "Global symbol ... requires explicit package name" on multiple lines
body: <p>I'm having trouble with this code. For some odd reason it generates error messages like</p>
  
  <blockquote>
    <p>Global symbol "$plan3" requires explicit package name</p>
  </blockquote>
  
  <p>on multiple lines for multiple variables.</p>
  
  <pre><code>#!/usr/bin/perl
  
  print "Content-type: text/html\n\n";
  
  use CGI qw(:standard);
  use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
  
  use strict;
  
  my $recipient = 'email@myemail.com';
  
  my $firstname, $lastname, $emailaddress, $paymentplan, $pricipalamount;
  my $errors, $fn1, $lnl2, $ea3, $pp4, $pa5;
  my $paymentamount;
  my $email;
  
  my $plan1 = 24, $plan2 = 48, $plan3 = 60;
  my $month;
  
  $firstname    = param( "firstname" );
  $lastname     = param( "lastname" );
  $emailaddress = param( "emailaddress" );
  $paymentplan  = param( "paymentplan" );
  
  $month           = param( "paymentplan" );
  $principalamount = param( "principalamount" );
  $errors          = 0;
  $fn              = 0;
  $ln              = 0;
  $ea              = 0;
  $pp              = 0;
  $pa              = 0;
  
  if ( $paymentplan == 1 ) {
      $paymentplan = $plan1;
  }
  
  if ( $paymentplan == 2 ) {
      $paymentplan = $plan2;
  }
  
  if ( $paymentplan == 3 ) {
      $paymentplan = $plan3;
  }
  
  $paymount = ( $amount * 1.14 ) / ( $plan - 2 );
  
  $email = "Welcome to the CSIT Loan Company, $firstname $lastname! \n\n  Your 
  email address is: $emailaddress \n  Your payment plan number is #$month \n  
  Your Prinicpal Amount is \$  $principalamount \n  And your total is 
  \$$paymentamount! \n\n  Thank you very much!";
  
  if ( index( $address, "@" ) == -1 ) {
      print "Please use an @ sign!";
      $errors = 1;
  }
  
  if ( $firstname eq "" ) {
      $fn     = 1;
      $errors = 1;
  }
  
  if ( $lastname eq "" ) {
      $ln     = 1;
      $errors = 1;
  }
  
  if ( $emailaddress eq "" ) {
      $ea     = 1;
      $errors = 1;
  }
  
  if ( $paymemtplan ne "24" &amp;&amp; $paymentplan ne "48" &amp;&amp; $paymentplan ne "60" ) {
      $pp     = 1;
      $errors = 1;
  }
  
  if ( $principalamount &lt; "5000" || $principalamount &gt; "50000" ) {
      $pa     = 1;
      $errors = 1;
  }
  
  if ( $errors == 0 ) {
  
      print MAIL "To: $recipient\n";
      print MAIL "From:apmycs2\n";
      print MAIL "Subject:Server Validation\n\n";
  
      print MAIL $email;
  
      close( MAIL );
      print "Success! this is an email to notify of successful validation";
  }
  else {
  
      if ( $fn == 1 ) {
          print "&lt;br&gt;Please Enter your First Name!&lt;br&gt;";
      }
  
      if ( $ln == 1 ) {
          print "&lt;br&gt;Please Enter your Last Name!&lt;br&gt;";
      }
  
      if ( $ea == 1 ) {
          print "&lt;br&gt;Please Enter a valid Email Address!&lt;br&gt;";
      }
  
      if ( $pp == 1 ) {
          print "&lt;br&gt;Please Enter a Payment Plan of 1, 2, or 3!&lt;br&gt;";
      }
  
      if ( $pa == 1 ) {
          print "&lt;br&gt;Please Enter a Principal Amount between 5000 and 50000!&lt;br&gt;";
      }
  }
  
  print "&lt;br&gt;&lt;p&gt;Thank you!&lt;p&gt;";
  </code></pre>