Private Sub btnCreate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
Me.intMode = ERV_GLOBAL.MB_ADD
Dim frm As Form = Me.ActiveMdiChild
If Not IsNothing(frm) AndAlso TypeOf frm Is MdiChildForm Then
Dim child As MdiChildForm = DirectCast(frm, MdiChildForm)
' ... now use "child" ...
child.Add()
Me.ShowHideControl(intMode, child.FormAuthority)
End If
End Sub
and the cast your reference to form like ActiveChild in Form3 and then you can access the required data member directly.