Sending plain text and html with MIME::Lite

I have an autoresponder script and am trying to set up an option in the script to send either plain text messages or html messages.
It currently will only send plain text with an attachment and the ability to personalize the messages.
The script uses MIME::Lite and sendmail. For the life of me I cannot figure out how to get this to work.
Below is the code for sending the messages.
Can any one help me?



sub sendmail{
     my($mon,$mday,$year) = ltime();
     my($to,$subject,$message,$path,$name,$idx,$username)=@_;
     my($email)=$to;
     $username=~/^\s*(\w{1,20})\s*(\w{0,20}).*$/;
     $secname=$2;$secname=~tr/A-Z/a-z/;$secname="\u$secname";
     $username=$1;$username=~tr/A-Z/a-z/;$username="\u$username";
     my($fromars,$namears,$unlink)=(getarlist("$path/$path.cfg"));
     $fromaddr="$namears<$fromars>";
     if ($unlink == 1) {$unlink="\r\n\r\n To unsubscribe:\r\n$scripturl?mode=r&a=$path&e=$to"}
     $to=~s/@/\@/;
     if ($secname ne ""){$secname=" ".$secname};
     $to="$username$secname <$to>";
     $name=~/.*\.(.*)/;
        my($real)="upfile$idx.$1";
     $path="$path/$real";
     my($current)="$mday/$mon/$year";
     $message=~s/\[FIRSTNAME\]/$username/gie;
     $message=~s/\[EMAIL\]/$email/gie;
     $message=~s/\[DATE\]/$current/gie;
     $message=~s/\[FULLNAME\]/$username.$secname/gie;
     $message.="\n\n$unlink\n\n";
     $subject=~s/\[FIRSTNAME\]/$username/gie;
     $subject=~s/\[EMAIL\]/$email/gie;
     $subject=~s/\[DATE\]/$current/gie;
     $subject=~s/\[FULLNAME\]/$username.$secname/gie;
     my($mime)=&mimeformat($name);
      my $msg = MIME::Lite->new
                 (Type =>'multipart/mixed',
                   From =>"$fromaddr",
               To =>"$to",
                Subject =>"$subject",
               Type => "TEXT",
               Data =>"$message");
     if($name ne ""){
              $msg->attach
               (Type =>$mime->[0],
               Encoding =>$mime->[1],
               Filename =>"$name",
               Path =>"$path",
                  );
     }
     MIME::Lite->send('sendmail',$mailprog);
      $msg->send;
}