Kevin,

My solution would be just for the mean time.

I need another help.

Code:
 Try
            For Each row As DataGridViewRow In DataGridView1.Rows
                Dim cell As DataGridViewCheckBoxCell = CType(row.Cells("checkboxchild"), DataGridViewCheckBoxCell)
                Dim cell2 As DataGridViewCheckBoxCell = CType(row.Cells("checkboxparent"), DataGridViewCheckBoxCell)
                If CBool(cell.Value) = True Then
                    stoid = CStr(row.Cells("STK_HOLD_CODE").Value)
                    itemlist.Add(stoid)
                End If
                If CBool(cell2.Value) = True Then
                    stoid = CStr(row.Cells("STK_HOLD_CODE").Value)
                    itemlist.Add(stoid)
                End If

            Next
            Dim strStrings() As String = CType(itemlist.ToArray(GetType(String)), String())
            Dim strJoinedString As String = String.Empty

            For Each astring In itemlist
                strJoinedString = strJoinedString
                strJoinedString = Join(strStrings, ",")
            Next
            MsgBox(strJoinedString)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        itemlist.Clear()
        
    End Sub
I want a validation preferably a msgbox.
There should be a checked Parent and Child. If the chkboxes are empty it will trigger a msgbox to inform the user to choose at least 1 Parent and Child.

Looking forward on your reply