You haven't provided any code so you will need to adapt this to your purposes
Code:
Private Sub btnOK_Click()
Dim i As Integer, aCtl As Control
For i = 1 To 8
With Me.Controls("TextBox" & i)
If .Value = "" Then
MsgBox "Nothing in this one"
.SetFocus
Exit Sub
Else
MsgBox .Name & vbCr & .Value
End If
End With
Next i
End Sub