[Sunhelp] XDM Troubles (BIG!)

[Martin]

Hello Folks,

I am new to the sun world ... and I try without any success to login via an
Xterminal to my SUN..

When I start I get the dtgreet screen on my monitor, which invites me to enter
name and password ... 
Unfortunately after the input of the correct name and password the screen is
resetted ....
So I am unable to log in .... 
Can someone enlighten me on this ...
Since it is probably a configuration error I have made ....

THANX !
Martin