print "<FORM METHOD=\"post\" ENCTYPE=\"multipart/form-data\">\n";
print "<INPUT TYPE=\"FILE\" SIZE=\"25\" NAME=\"UPLOAD\">\n";
print "<input type=\"hidden\" name=\"login\" value=\"$login\">\n";
print "<input type=\"hidden\" name=\"password\" value=\"$password\">\n
+";
print "<input type=\"submit\" value=\" Send File \">\n";
print "</FORM>\n";
[download]

If you don't use a module to construct your form, at least use here-docs:

print <<"END_OF_FORM";
  <FORM METHOD="post" ENCTYPE="multipart/form-data">
  <INPUT TYPE="FILE" SIZE="25" NAME="UPLOAD">
  <input type="hidden" name="login" value="$login">
  <input type="hidden" name="password" value="$password">
  <input type="submit" value=" Send File ">
END_OF_FORM
[download]

Keep your code readable. Ah, and don't pass around hidden fields with username/password, use e.g. a cookie to store a session key. See Basic cookie management.

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}