[winGRASS] problems with tcltkgrass

[grass at karsten-lessing.de]

Hello,

My PC is running under Win2000 and I have some problems with tcltkgrass:

Definitively I installed the whole package of cygwin which I´ve got
from:
http://xfree86.cygwin.com/
so also xFree86 und X11R6.4 should be came with it !

I am also sure that I installed the right package of GRASS with xserver
support and the spearfish dataset!

To start GRASS with tcltk I do the following:

start Cygwin as described under:
http://grass.baylor.edu/grass5/binary/windows_cygnus/cygwin_grass50bininstall.html

In the appearing terminal I type in:
"startxwin.bat"

After starting grass5 and the spearfishdataset 
GRASS:~ > 
appears regular.

But after calling up:
"tcltkgrass&" 
the following error promt appears:


/usr/X11R16/bin/xwininfo: unable to open display"
usage: /usr/X11R16/bin/xwininfo [-options ...]

where options include:
-help    print this message
-display host dpy ....
....
... 
..
.

while executing
"exec xwininfo [winfo id .w_g] | grep -i Corners"
   invoked from within
"scan [exec xwininfo -id [wininfo id .w_g] < grep -i Corners] {%*s %d%d}
dx dy"
   (file "/usr/local/grass5/tcltkgrass/main/gui.tcl" line 1887)
   invoked from within
"source $env(TCLTKGRASSBASE)/main/gui.tcl"
   (file "/usr/local/grass5/bin/tcltkgrass" line 21)


can anybody help ???

best regards 
Karsten