whenever I try to do 'apt-get install nvidia-glx', I get the following error:

dpkg-divert: `diversion of /usr/lib/libGL.so.1 to /usr/lib/nvidia/libGL.so.1.xlibmesa by nvidia-glx' clashes with `diversion of /usr/lib/libGL.so.1 to /usr/lib/fglrx/libGL.so.1.xlibmesa by xorg-driver-fglrx'
dpkg: error processing /var/cache/apt/archives/nvidia-glx_1.0.8774+2.6.17.5-11_i386.deb (--unpack):
subprocess pre-installation script returned error exit status 2
Errors were encountered while processing:
/var/cache/apt/archives/nvidia-glx_1.0.8774+2.6.17.5-11_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)