Are there rules for case sensitivity for objects?

I've run into weird bugs especially when attempting to activate one form object from another form object such that

frmCashDetail.cmdNew.setfocus()
FRMCASHDETAIL.cmdNew.setfocus()
frmcashdetail.cmdNew.setfocus()

are all different. The only way I can figure out what the correct name is to look in the debugger to find out what _Screen.ActiveForm.Name is.

This makes me nervous...especially because only the first part of the object name, (the form name) seems to exibit the problem, the buttons and text box names seem not to care if they are uppoer or lower case.

Advice appreciated.

--- Larry