grammar/wording

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@7315 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

doc/ffmpeg-doc.texi

@@ -41,14 +41,14 @@ standard mixer.
 
 @section X11 grabbing
 
-FFmpeg can grab X11 display.
+FFmpeg can grab the X11 display.
 
 @example
 ffmpeg -f x11grab -vd x11:0.0 /tmp/out.mpg
 @end example
 
-0.0 is display.screen numbers of your X11 server.
-You can check $DISPLAY variable.
+0.0 is display.screen number of your X11 server, same as
+the DISPLAY environment variable.
 
 @section Video and Audio file format conversion