Mac server OSX 10.8.2 Netistall doesn't have image, how can I fix this?

I tried to switch on Netinstall on just on just brand new Apple mini server, all the data have filed and green light is on, except of Netinstall which requesting me to add an image and file in the library/netboot/ is empty for that. If even I try to add it on the NEtinstall page, there small gear tab blanked and cn not modified at all whatever I did, I have not modified any thing there - so that is suprice why on the new apple happening with me that, may be a problem in a software or I just don't know somne thing. On the apple support page also there is no information for OSX10.8.2 server how can I fix this problem, Could some one explain how is possible to finaly make an image and make netinsall to work, I will be much appreciated for that,