Sending mail attachment through PL/SQL, message not showing in mail body

Question

Dear All,
I am sending mail with attachment(pdf file) through oracle.
file is attached and showing.
problem is,message is not displaying in message body, it's displaying also in file attachment.
i want to show message in body.
mime setting is as follow:
mesg := mesg || 'Mime-Version: 1.0' || crlf ||
'Content-Type: multipart/mixed; boundary="' || boundary || '"' ||
crlf || crlf ||
'This is a Mime message, which your current mail reader may not' || crlf ||
'understand. Parts of the message will appear as text. If the remainder' || crlf ||
'appears as random characters in the message body, instead of as' || crlf ||
'attachments, then you''ll have to extract these parts and decode them' || crlf ||
'manually.' || crlf || crlf;
utl_smtp.write_data(conn,mesg);"
-- Write the text message or message file or message CLOB, if any
if (message is not null and length(message) > 0) or
clob_message is not null then
mesg := '--' || boundary || crlf ||
'Content-Type: text/plain; name="message.txt"; charset=US-ASCII' ||
crlf ||
'Content-Disposition: inline; filename="message.txt"' || crlf ||
'Content-Transfer-Encoding: 7bit' || crlf || crlf;
utl_smtp.write_data(conn,mesg);
if instr(message,'/') = 1 or instr(message,':\') = 2 or
instr(message,'
') = 1 then
split_path_name(message,directory_path,file_name);
append_file(directory_path,file_name,'text',conn);
utl_smtp.write_data(conn,crlf);
elsif message is not null and length(message) > 0 then
utl_smtp.write_data(conn,message);
if length(message) = 1 or
substr(message,length(message)-1) != crlf then
utl_smtp.write_data(conn,crlf);
end if;
elsif clob_message is not null then
append_file(null,'message.txt','text/plain',conn,clob_message);
end if;
end if;please help

Answer 1

dear, when i open this auto generated mail into outlook express, then message is showing properly, but in microsoft outlook 2007, it's showing message as text attachment.
I appreciate any hint...
thanx.