Dim rsMain As DAO.Recordset
    Dim rsSate As Dao.Recordset
    Dim State  As ComboObject

    Set rsMain = CurrentDb().OpenRecordset("qry_Main")
    Set rsState = CurrentDb().OpenRecordset("tbl_State")     'SELECT StateID, State FROM tbl_State;
    Set State = iGrid2.Combos.Add("State")
    
    State.FillFromRS rsState, "State", "StateID"
        
    With iGrid2.AddCol(sKey:="State", sHeader:="State")
        .eType = igCellTextCombo
        .sCtrlKey = "State"
    End With
    
    iGrid2.FillFromRS rsMain

    Set rsMain = Nothing
    Set rsState = Nothing

Option Compare Database

Private Sub igrid1_formating()
'formatting
    With iGrid1.Header
        .ForeColor = vbBlack
        .Font.Size = 12
        .Font.Bold = True
        .UseXPStyles = False
    End With

    With iGrid1.Font
        .Size = 10
    End With

    With iGrid1
        .AutoHeightRows
    End With
    
    For iCol = 1 To iGrid1.ColCount
       iGrid1.AutoWidthCol iCol
    Next
End Sub

Private Sub Form_Load()
    Dim rsMain  As DAO.Recordset
    Dim rsSec   As DAO.Recordset
    
    Dim Sec     As ComboObject
    
    Set rsMain = CurrentDb().OpenRecordset("tbl_Main")
    Set rsSec = CurrentDb().OpenRecordset("tbl_Sec")
    
    Set Sec = iGrid1.Combos.Add("Sec")
    
    iGrid1.BeginUpdate
    
    'properties
    iGrid1.MultiSelect = True
    
    'populate dropdowns
    Sec.FillFromRS rsSec, "Sec", "SecID"
    
    'add columns
    With iGrid1
        With .AddCol(skey:="MainID", sHeader:="ID")
        End With
        With .AddCol(skey:="SecID", sHeader:="Sec")
            .eType = igCellCombo
            .sCtrlKey = "Sec"
        End With
        With .AddCol(skey:="Other", sHeader:="Other")
        End With
    End With
    
    'populate columns
    iGrid1.FillFromRS rsMain
    
    'formatting
    Call igrid1_formating

    iGrid1.EndUpdate
    
    Set rsMain = Nothing
    Set rsSec = Nothing
End Sub