Sheet Change Question

Hey guys, I have a user function that I want to recalculate when I switch between sheets. I am already using Application.Volatile, but it still won't recalculate when I focus on a different sheet.

Any ideas?

A-ha! Figured it out.

Private Sub object_SheetActivate(ByVal Sh As Object)
Calculate
End Sub

placed in the ThisWorkbook module

I would still be interested to learn a bit of code that I can put directly into my User Function that can have the same effect.