Question to InstallVersion, updating plugins ... !

Hi !

I have written a .xpi for installing my plugin. All works fine, I used a
PLID, handle the First-Install-Problem...

But now I want to update my plugin with new releases.

I have read the xpinstall doc (.pdf) but I don't understand what I have to
do with "InstallVersion", InstallTrigger.compareVersion() and so on.

What code must placed in Javascript (webpage) and what into my install.js.

Are there anwhere more examples ?

Thanks a lot

.stefan