Problem with Form_BeforeUpdate

Problem with Form_BeforeUpdate
at the time of field validation in the form
drives me once I close the form and I want to return to the field where needed to fill the field thanks in advance masters

I have this code but just close the form

If IsNull([Organizacion]) Then
MsgBox (" Introduzca la organizacion.")
Cancel = True
Me!Organizacion.Undo
the form are emerging

Use the:

Me.YourField.SetFocus

In the Open of the form.

p.s. my english is bad

I have this code in my form



Option Compare Database
Dim rs As Object
Dim Modificado As Boolean
Private Const LaTabla As String = "nombre de la tabla"
------------------------------------------
Private Sub Form_Load()
Me.YourField.SetFocus
Set rs = CurrentDb.OpenRecordset(LaTabla)
End Sub
--------------------------------------------
Private Sub Form_BeforeUpdate(Cancel As Integer)

If IsNull([Organizacion]) Then
MsgBox (" Introduzca la organizacion.")
Cancel = True
Me!Organizacion.Undo
End If

End Sub

------------------------------------------------
Private Sub Form_Dirty(Cancel As Integer)
Modificado = True
End Sub
-----------------------------------------------

try the code you gave me and I get the form does not always go to the field with the focus, the form is closed <>

How do I get in Form_Dirty or Form_BeforeUpdate me back to the Save button
that's where I'm validating the fields, because Form_BeforeUpdate is the vanishing point to not go through form validation and if I put validation in Form_BeforeUpdate only recognize me the first field to validate after me and writes out the information form and is I do not want you to tell me if I want to save changes whether or not to give if I go again for validation or to send me to the Save button
had already call Save () but I can not work someone's take hand in this, thank you very much in advance.

I will not understand me or is that enverdar can not??
will not do this validation events made ​​on the form???