Possible to get vbulletin version variable?

[dicegame]

Hey I'm trying to create a logout script on an external page. I've got the logout script to work for 3.8.1

Does anyone have any documentation of what version use the different types of logout code. I've noticed that 3.8.1 uses something different from 3.6.x etc

Also is there anything in the database which referers to the Vbulletin version maybe a phrase of some sorts?

I'm trying to create a logout script which knows the version and then generates the appropriate logout code for the different versions.

Thanks,
Thomas