my $formStatus = $query->param('submitButton');

my $sql13 = "SELECT name, sub_name, good_high, critical_low, warning_low, warning_high FROM comm_desk_thresholds WHERE user = ? ";
my $sth13 = $dbh->prepare($sql13);
$sth13->execute($userName);

my @compare_1;
while (my @row_13 = $sth13->fetchrow_array) {#Storing list of values when page is loaded before submit button is clicked
    push @compare_1, @row_13;
}

if ( $formStatus eq "Submit" ) { # This code will run only when Submit button is clicked

    my $sql14 = "SELECT name, sub_name, good_high, critical_low, warning_low, warning_high FROM comm_desk_thresholds WHERE user = ? ";
    my $sth14 = $dbh->prepare($sql14);
    $sth14->execute($userName);
    print $fh "After $sql14 executed (Performance_2): ". localtime()."\n";
    my @compare_2;
    while (my @row_14 = $sth14->fetchrow_array) {#Storing list of values after submit button is clicked
        push @compare_2, @row_14;
    }

    my @diff;
    for ( my $i=0; $i <($#compare_1+1); $i++)
    {
        if ( $compare_1[$i] ne $compare_2[$i] )
        {
            push @diff, $compare_2[$i];
        }
    }
	#Run business logic for only those elements in @diff.
}