installation

Hello, I have installed arklinux on my system, and it boots and runs fine up 
until the desktop is supposed to show up, then the screen never comes on. I 
need to know a command to enter at boot to force it to a lower resolution. I 
have tried screen=800x600 fb=800x600 and such, nothing seemed to work. All the 
graphics are nice up until the login point, and I never see that or anything 
else. A command will fix me right up! Thanks in advance!

Kelly