LinuxQuestions.org - Can I stop autologin with a script?

I am running Suse Linux 9.2 Pro, full install.

My problem: My cousin comes over from time to time, and although he thinks he knows a lot about computers, he really doesn't. The problem is that he will often try to change settings and end up destroying everything on my computer, forcing me to reformat. I have the computer set up so he can just turn it on, and it will login as guest. If I don't want him using the computer, I would type:

Code:

xlock -mode laser -timeout 1 -password "System Locked by Administrator" -invalid "Access Denied"

This worked until he figured out that if he just pulled the plug and restarted the computer, it would log back in for him and he could use the computer again no problem. Is there a way that with the click of a button I can lock the screen and disable the "autologin on restart" but make it so when I type in the password, the program will unlock the screen and re-enable the "autologin on restart" I guess the best thing would be a C++ program that can enable/disable the autolock, and would call xlock.

something to the effect of:

int main(){
disable autologin
call xlock
while xlock does not return success, keep looping
enable autologin
return 0;
}

I can put this executable on the desktop, and with a single click accomplish my goal. I would be VERY thankful if someone could write a quick program to do this (I understand you guys have lives and probably don't want to do that), so if anyone knows of a quick script or a prewritten program that does this I would be very thankful!