Evaluate Null values

[rwalle]

HI
I have some problems to evaluate null values,[EmpName] is a string form field that display employee names if an employee is in the table where form is based it works fine for employees that are in the table but when a null val is displayed on this field the If statement doesn't work am I missing something or is there a diferent way to evaluate empty string field values ??

Tks for your help
Raymundo Walle

If Me.EmpName = "" Then
MsgBox "Usted no esta registrado en este sistema", 16, "Falla de Autentificacion"
DoCmd.Close
Else
DoCmd.OpenForm "Principal", acNormal, , , acFormEdit, acWindowNormal, ""

End If
Debug.Print Me.EmpName
End Sub

[Mihail]

If IsNull(Me.EmpName) Then ...

.

[Stewart Ross]

Even simpler is just

If Nz(Me.EmpName) = "" Then

In this type of usage Nz returns an empty string if faced with a null - which is exactly what you want.

There is an alternative use of Nz which is not required in this case:

someval = Nz(anothervalue, returnvalue)

The short form listed above is exactly the same in its effect as the following full usage of Nz:

If Nz(Me.EmpName, "") = "" Then

-Stewart

[rwalle]

Mihail, Stewart:
thanks for your response the form is doing what it's intended to

Thanks

Raymundo Walle