problem running xserver

hi,
i am having a problem with the xserver on my system running redhat 7.2. i 
had accidentally made some modifications to the pam files. now i am able 
to run the xserver only as root. when i try to run it as any other user i 
get the error:
	Fatal server error:
	PAM authentication failed, cannot start xserver.
	Perhaps you do not have console ownership?


any ideas as to how this happened and what i could do?
thanks.
prashant

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