#!/usr/bin/perl -w
#Volunteer.pl - Insert Volunteers into database

use strict;
use DBI;
use CGI;
my $query = CGI::new();
my ($dbh, $sth, $sql, $name, $date, $sub_parent, $col);
my @volunteer_date  = $query->param("Volunteer");
my $parent = $query->param("Parent");
#my $user = $query->REMOTE_USER();
my $user = $ENV{"REMOTE_USER"};
#my $user = "<Player Name>";
#my $name = undef;
#my $parent = "Father";
#my @volunteer_date = ("2002-01-18");

print $query->header(),
      $query->start_html (-title=>'Volunteer List Form',
                          -link=>'#FFFFFF',
                          -vlink=>'99FF99',
                          -alink=>'black',
                          -style=>{'-src'=>'/CSS/stylesheet.css'});
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# store subparent for each parent
my %parent_hash = ( 'Father' => 'Mother',
                    'Mother' => 'Father' );

if ( @volunteer_date ){
if (exists $parent_hash{$parent}) {
  my $sub_parent = $parent_hash{$parent};

  for $col ( $parent, $sub_parent ) {
      $sql = "select $col from Roster where User=?";
      $sth = $dbh->selectcol_arrayref( $sql, undef, $user );
print $query->h1({-align=>'center'},"$sub_parent, $parent, $user");
    if ( @$sth && $sth->[0] ) {  # any rows returned?
       $name = $sth->[0];  # take first one
      #last;
    }
  }
}

print $query->h1({-align=>'center'},"THANK YOU FOR SIGNING UP $name");

   foreach $date ( @volunteer_date ) {

        $sql = "select distinct Volunteer from Volunteer where Volunte
+er =? and Date =?";
        my $sth = $dbh->selectcol_arrayref( $sql, undef, $name, $date 
+);

#Verify the parent is not signed up.
           if( @$sth ) {
             print $query->h1({-align=>'center'}, "You are already sig
+ned up for this date: $date");
             last;
}
  }
}

print $query->h1({-align=>'center'},"THANK YOU FOR SIGNING UP $name");

   foreach $date ( @volunteer_date ) {

        $sql = "select distinct Volunteer from Volunteer where Volunte
+er =? and Date =?";
        my $sth = $dbh->selectcol_arrayref( $sql, undef, $name, $date 
+);

#Verify the parent is not signed up.
           if( @$sth ) {
             print $query->h1({-align=>'center'}, "You are already sig
+ned up for this date: $date");
             last;
           } #end if statement

#process the information and update the schedule.
           else{
        my $sql = "select max(Number) from Volunteer where Date =? and
+ Volunteer = 'TBD'";
        my $number = $dbh->selectcol_arrayref($sql, undef, $date);

        $sql = "update Volunteer set Volunteer = '$name' WHERE Date = 
+'$date' and Number = $number->[0]";
        $sth = $dbh->prepare($sql) || die "prepare: $$sql: $DBI::errst
+r";
        $sth->execute || die "execute: $sql->[0]: $DBI::errstr";

        print $query->h1({-align=>'center'}, "You signed up for this d
+ate $date");

$sth->finish ();
$dbh->disconnect ();

         } #end else statement
   } #end foreach loop
} #end if volunteer_date check
else{
        print $query->h1({-align=>'center'}, "You did not select a dat
+e");

} #end else volunteer_date check

#       print $query->end_html;

        print $query->h2({-align=>'center'},
              $query->a({href=>'../UnSignup.pl'}, 'UNDO SIGNUP'), '&nb
+sp',
              $query->a({href=>'../BobSchedule.pl'}, 'BOBS SCHEDULE'),
+ '&nbsp',);
              $query->end_html;
        print $query->h3({-align=>'center'},
              $query->a({href=>'Volunteer.pl'}, 'BACK'), '&nbsp',);
              $query->end_html;
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I checked the %ENV with the diagnostic script it shows REMOTE_USER is there and has the correct value. However it still does not capture the value for my script.

  my $user = $ENV{"REMOTE_USER"}; should be picking up the username if the diagnostic script shows that it's there. When you set $user yourself, are you using exactly the same username that the diagnostic script prints?

Were this me, I would do

print $query->header(),
      $query->start_html (-title=>"Volunteer List Form ($user)",
      ...
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to verify what I'm getting. Then I'd focus on the query logic.