I've searched the forums and I've tried google but I haven't been able to find an answer to my problem. Let me apologize in advance if this has been addressed elsewhere.

I have RedHat 9 installed on my PC. Depending on what I am doing at the time, I have one of my two monitors plugged in (we have on 21" and one 15"). When I want to use a certain monitor I must manually edit XF86Config to change the HorizSync and VertRefresh in Section "Monitor" and then startx.

Is there a way to have the system detect which monitor is attached and use those settings? Can I add a second "Identifier" in the Section "Monitor"?

Thanks in advance for the help and again I'll apologize if this has been answered before.

You can have two XF86Config files, one for each monitor. Name them XF86Config.monitorname. When you switch just
cp XF86Config.monitorname XF86Config

You'll want to do the same with XF86Config-4