i am using a textbox in the main form to transfer the Yr/Mth into the table. (refer to qp.zip)

now my problem is, how do i prevent duplicate records into the table?

e.g: currently whenever i scroll ard the months control in the form, i will get duplicate Mth/Yr into the table. how do i prevent that from happening?

i only want to have updated data inside the Mth/Yr table instead of duplicated Mth/Yr

Public Sub PutInMonthlyRecords()

Dim sql As String
Dim Db As DAO.Database
Dim rs As DAO.Recordset
Dim f As Form
Dim MthYr As String

Set f = Forms!frmQpi

MthYr = f("txtMthYr")

sql = "SELECT * FROM [tblQpiMonthly] WHERE (([tblQpiMonthly].[Input MthYr] = 'MthYr' ));"

Set Db = CurrentDb()
Set rs = Db.OpenRecordset(sql)


If rs.RecordCount = 0 Then
If (f!txtTotalPF) = 0 Then
Exit Sub
End If

rs.AddNew
rs![Input MthYr] = f("txtMthYr")
rs![Monthly TotalPF] = f("txtTotalPF")
rs![Monthly Rejection] = f("txtTotalAvoid")
rs![Monthly TotalAvoid] = f("txtRejection")

rs.Update

Else
If (f!txtTotalPF) = 0 Then
rs.Delete

Exit Sub
End If


rs.Delete
rs.AddNew
rs![Input MthYr] = f("txtMthYr")
rs![Monthly TotalPF] = f("txtTotalPF")
rs![Monthly Rejection] = f("txtTotalAvoid")
rs![Monthly TotalAvoid] = f("txtRejection")

rs.Update

End If


Db.Close

End Sub

here is the function which i re-edited. the codes that were not affecting the program have been deleted.

Public Sub PutInMonthlyRecords()

Dim sql As String
Dim Db As DAO.Database
Dim rs As DAO.Recordset
Dim f As Form


Set f = Forms!frmQpi
Set Db = CurrentDb()


sql = "SELECT * FROM [tblQpiMonthly];"

Set rs = Db.OpenRecordset(sql)

If (f!txtTotalPF) = 0 Then
Exit Sub
End If

If (f!txtTotalPF) = 0 Then
Exit Sub
End If

If (f!txtTotalPF) = 0 Then
Exit Sub
End If

rs.AddNew

rs![Input MthYr] = f("txtMthYr")
rs![Monthly TotalPF] = f("txtTotalPF")
rs![Monthly Rejection] = f("txtTotalAvoid")
rs![Monthly TotalAvoid] = f("txtRejection")

rs.Update


Db.Close

End Sub

Basically, when the record is not found in the table, it will add the new record. if the record is found in the table, it should edit the record instead of adding the same record into the table.