X and Fluxbox :: 1024x768 resolution on Xfree and nVIDIA

Hello everyone.
I`ve installed the XFree86.dsl extension and after that i`ve installed the nvidia.dsl module but i have a little problem , i cant set the display resolution to 1024x768.

How can i set it up ?

Please , help.

With respect ,

Aygun

original here.