New line caariage return

I want to generate some files at my job on a NT machine. When I press the button "SAVE" I want the file to be saved on a UNIX machine by sending it by FTP.
This is working well but when I'm opening the file on the UNIX machine I see a square on the place where you should have a carriage return. When I'm opening the file on the NT machine I don't see squares (control characters).

I tried to send the file in FTP_Binary and in FTP_ASCII but I have the problem in the two cases.

The text I am sending is like:
$textfield="Hello this is a test\n This is a test2\n And a lot more";
$fp = fopen($temp, "w+");
$write=fwrite($fp, $textfield);

I tried to upload the generated files with an ordinarry FTP program (like WSFTP) and there I didn't encounter this problem //AND i saved my file as unix format with textpad and uploaded it with my FTP script. (FTP program does auto convert the file to unix format)
So i want to do the DOS format to UNIX format conversion it with a script.
I read in a nwsgrp that WIN machine = \r\n and on Unix machine = \n. (new line)
But I am saving it with "\n", so this is the format for an UNIX machine.

When I open my file with a hex editor on windows i see OD OA = \r\n. So it seems that Windows automatically adds the \r.
I tried then to use $textfield=str_replace("\r\n","\n",$textfield);
But still the same problem.
CAN PLEASE SOMEONE HELP ME.
Thanks in advance,
Frederick

Try:

$textfield = preg_replace("/(\015\012)|(\015)|(\012)/","",$textfield);

or maybe:

$textfield = preg_replace("/(\015\012)|(\015)|(\012)/","\n",$textfield);

I found the solution. I have to open my file binary to write:
fopen ($test,wb+)