I am trying to perform a procedure which checks whether a customer in a table already exists by comparing First, Last Name and Post Code. Unfortunatly I have a probelm in the FirstName variable. This is what I have tried:

Private Sub txtPCode_AfterUpdate()

Dim FirstName As String
Dim LastName As String
Dim PCodeID As String
Dim LCustomerID As String
Dim FCustomerID As String

FistName = ""
LastName = ""
LCustomerID = ""
FCustomerID = ""
PCodeID = ""

LastName = DLookup("LName", "CustomerInfo", "LName = Forms![Add_Customer]![txtLName]")
LCustomerID = DLookup("CustID", "CustomerInfo", "[CustomerInfo]![LName] = Forms![Add_Customer]![txtLName]")

FirstName = DLookup("FName", "CustomerInfo", "[CustomerInfo]![CustID] = LCustomerID")

FCustomerID = DLookup("CustID", "CustomerInfo", "[CustomerInfo]![CustID] = LCustomerID")

PCode = DLookup("CustID", "CustomerInfo", "[CustomerInfo]![PCode] = Forms![Add_Customer]![txtPCode]")

If ((IsNull(FirstName) And IsNull(LastName) = False) And (FCustomerID = LCustomerID = PCodeID)) Then
MsgBox (FirstName + " " + LastName + " is an existing Customer, CustID = " + CustomerID)
Forms![Add_Customer]![txtFName] = ""
Forms![Add_Customer]![txtLName] = ""

End If

End Sub

But this did not work So I tried this: (Everything else same apart from

FirstName = DLookup("FName", "CustomerInfo", "[CustomerInfo]![CustID] =(DLookup("CustID", "CustomerInfo", "[CustomerInfo]![LName] = Forms![Add_Customer]![txtLName]"))")



Can anyone help me with this problem? I will be very greatful