Dim con As OleDb.OleDbConnection
    Dim query As String
    Public Function openDB()

        Dim connectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=test.mdb"
        con = New OleDb.OleDbConnection(connectionString)

        'Dim ds As New DataSet
        'Dim da As OleDb.OleDbDataAdapter
        'Dim dt As DataTable
        'Dim dr As DataRow
        'da = New OleDb.OleDbDataAdapter(query, con)

        con.Open()

    End Function

For Each rDataRow In rDataTable.Rows
            cmb_inv_reporter.Items.Add(rDataRow.Item("Name"))
        Next

    Private objConnection As OleDbConnection
    Private objCommand As OleDbCommand
    Private objDataAdapter As OleDbDataAdapter
    Private objDataTable As DataTable

        'Initialize the Connection object
        objConnection = New OleDbConnection(strConnectionString)

        'Initialize the Command object
        objCommand = New OleDbCommand("SELECT ID, FirstName " & _
            "FROM Employee", objConnection)

        'Initialize the DataAdapter object and set the SelectCommand property
        objDataAdapter = New OleDbDataAdapter
        objDataAdapter.SelectCommand = objCommand

        'Initialize the DataTable object
        objDataTable = New DataTable

        'Populate the DataTable
        objDataAdapter.Fill(objDataTable)

        'Bind the DataTable to the ComboBox
        ComboBox1.DataSource = objDataTable
        ComboBox1.DisplayMember = "FirstName"
        ComboBox1.ValueMember = "ID"

        'Clean up
        objDataAdapter.Dispose()
        objDataAdapter = Nothing
        objCommand.Dispose()
        objCommand = Nothing
        objConnection.Dispose()
        objConnection = Nothing
    End Sub
End Class

----------------

Option Strict Off
Option Explicit On
Module gbl
    Dim con As OleDb.OleDbConnection
    Dim query As String
    Dim com As OleDb.OleDbCommand
    Dim da As OleDb.OleDbDataAdapter
    Dim dt As DataTable

    Public Function openDB()
' Open the database
        Dim connectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=TEST.mdb"
        con = New OleDb.OleDbConnection(connectionString)

        con.Open()

        'populates Reporters
        com = New OleDb.OleDbCommand("SELECT * FROM Reporters ORDER BY Name", con)
        da = New OleDb.OleDbDataAdapter
        da.SelectCommand = com
        dt = New DataTable
        da.Fill(dt)

        frm_invoices.cmb_inv_reporter.DataSource = dt
        frm_invoices.cmb_inv_reporter.DisplayMember = "Name"
        frm_invoices.cmb_inv_reporter.ValueMember = "ID"

        da.Dispose()
        da = Nothing
        com.Dispose()
        com = Nothing

        'populates Client Information
        com = New OleDb.OleDbCommand("SELECT * FROM Clients ORDER BY clients.[Client Name]", con)
        da = New OleDb.OleDbDataAdapter
        da.SelectCommand = com
        dt = New DataTable
        da.Fill(dt)

        frm_invoices.cmb_inv_client.DataSource = dt
        frm_invoices.cmb_inv_client.DisplayMember = "Client Name"
        frm_invoices.cmb_inv_client.ValueMember = "ID"

        frm_invoices.cmb_inv_cid.DataSource = dt
        frm_invoices.cmb_inv_cid.DisplayMember = "ID"
        frm_invoices.cmb_inv_cid.ValueMember = "ID"

        frm_invoices.cmb_inv_firmID.DataSource = dt
        frm_invoices.cmb_inv_firmID.DisplayMember = "FirmID"
        frm_invoices.cmb_inv_firmID.ValueMember = "ID"

        da.Dispose()
        da = Nothing
        com.Dispose()
        com = Nothing

        'populates Firms
        com = New OleDb.OleDbCommand("SELECT * FROM Firms ORDER BY [Firm Name]", con)
        da = New OleDb.OleDbDataAdapter
        da.SelectCommand = com
        dt = New DataTable
        da.Fill(dt)

        frm_invoices.cmb_inv_firm.DataSource = dt
        frm_invoices.cmb_inv_firm.DisplayMember = "Firm Name"
        frm_invoices.cmb_inv_firm.ValueMember = "ID"

        da.Dispose()
        da = Nothing
        com.Dispose()
        com = Nothing

        Return ""
    End Function
    Public Function DBstate()
        Select Case con.State
            Case 0
                frm_invoices.ToolStripStatusLabel1.Text = "Database Disconnected"
            Case 1
                frm_invoices.ToolStripStatusLabel1.Text = "Database Connected"
        End Select
        Return ""
    End Function
    Public Function checkDB()

        Select Case con.State
            Case 0
                MsgBox("Disconnected")
            Case 1
                MsgBox("Connected")
        End Select
        Return ""

    End Function

    Public Function closeDB()
        con.Dispose()
        con.Close()
        Return ""
    End Function
End Module