[ubuntu] xconfig problems Desktop Effects Customization Question

HI there I am trying to figure out the problems I am having and I am having a problem with xconfig.........

here is the terminal code I get when I try to get it going......

Code:

Using X configuration file: "/etc/X11/xorg.conf".

WARNING: The CorePointer device was not specified explicitly in the layout;
         using the first CorePointer in the config input list.


WARNING: The CoreKeyboard device was not specified explicitly in the layout;
         using the first keyboard device.


ERROR: Unable to write to directory '/etc/X11'.

mike@Dads-Computer:~$

Any help would be greatly appreciated thanx.....