#!/usr/bin/perl -w

use strict;
my $filename = "File_Name_One";
my $letter = "A";

my $dbh = DBI->connect("DBI:ODBC:databasename", "","")
                   || die "error: ($DBI::errstr)\n";

my $firstvar = $dbh->quote($filename);
my $secondvar = $dbh->quote($letter);

my $statement = "Insert into tableOne (filename, letter)
  values ($firstname, $letter)";

# Now you need to actually execute the statement
$dbh->do( $statment ) || die "error: $dbh->errstr\n";

# rest of code