fix poor english

doc/README.txt

-$Id: README.txt,v 1.5 2003-01-24 23:13:36 geuzaine Exp $
+$Id: README.txt,v 1.6 2003-02-21 06:56:57 geuzaine Exp $
 
 For Windows versions of Gmsh only:
 ==================================
@@ -6,13 +6,13 @@ For Windows versions of Gmsh only:
 1) About opengl32.dll and glu32.dll:
 
 If your system complains about missing opengl32.dll or glu32.dll
-libraries, OpenGL is not properly installed on your system. Go
-download OpenGL on Microsoft's web site!
+libraries, then OpenGL is not properly installed... Go download OpenGL
+on Microsoft's web site or on http://www.opengl.org.
 
 2) About cygwin1.dll:
 
 If you plan to use other programs than Gmsh that depend on the
-cygwin1.dll library, you should keep only one version of the library
+cygwin1.dll library, you should keep only one version of this library
 on your system (i.e., move cygwin1.dll to the Windows system
 directory--usually C:\Windows\System\--and suppress all other versions
 of cygwin1.dll). Failing to do so may result in an incorrect behaviour