If you want to fire the Dirty event on what you call the Main Form (which would actually be the Parent Form) and you want to do it from the Dirty event in your Sub-Form located in that Parent Form then this is what you will need to do:
Change the declarationIn the Parent Form's OnDirty event code declaration, change the Private to Public so that it reads:
Public Sub Form_Dirty(Cancel As Integer)
MsgBox "Main Dirty"
Then in the OnDirty event for your SubForm, you can fire the Dirty event of the Parent Form like this:
Self Taught In ALL Environments.....And It Shows!