Binaryworld - IsFormModal - Determines whether a form is modal ... [ VB -> Forms & Controls ]

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" _
  (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Const GWL_STYLE = (-16)
Const WS_DISABLED = &H8000000

' Return True if the form is modal
'
' Note: if an application has only one visible
'    form, this function considers it as modal

Function IsFormModal(frm As Form) As Boolean
  Dim f As Form

  For Each f In Forms
    If Not (f Is frm) Then
      If (GetWindowLong(f.hWnd, GWL_STYLE) And WS_DISABLED) = 0 Then
        ' there is another enabled form, so this form
        ' can't be modal
        Exit Function
      End If
    End If
  Next
  ' all other forms are disabled, therefore this form is modal
  IsFormModal = True

End Function