How can i make auto increment in my textbox vb.net and database of access

[prince29]

When i run the program i got the patient id = 1 then register again then patient id = 2 but when i register again it remain 2 . what is the problem with my code ?

Try
            cn = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source= " & Application.StartupPath & "\HMSdb.accdb")
            cn.Open()
            cmd = New OleDbCommand("select * from PatientRegistration ", cn)
            Dim dr As OleDbDataReader = cmd.ExecuteReader
            If dr.Read Then
                txtPatientID.Text = dr.Item(0) + 1
            Else
                txtPatientID.Text = "1"
            End If
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

[Luk3r]

txtPatientID.Text = dr.Item(0) + 1

I think this is your issue. dr.Item(0) is selecting the first record and adding 1 to it every time, which will always equal 2. You need to have it setup with an integer variable and do something like this:

Dim i as integer
txtPatientID.Text = dr.Item(i)
i = i + 1

The integer variable should be global.