Como criar dois Popup ao mesmo um para abrir _blank e _self

<!-- JAVASCRIPT -->
<script>
        var url;
        function open_cadastro(url)
        {
            window.open(url,'_blank','toolbar=no, location=no,status=no,menubar=no,scrollbars=yes,resizable=no, width=420,height=400,left=430,top=23')
        }
        function open_imprimir(url)
        {
            window.open(url,'_self')
        }
<script>


<!-- HTML -->
 <ul class="button_tam">
                    <li><a href="javascript:void(0)" onclick="open_cadastro('<?php echo site_url("site/imprimir/$row->oferta_id"); ?>');open_imprimir('<?php echo site_url("site/imprimir_view/$row->oferta_id"); ?>');" title="Imprimir Cupom" class="large button blue">Imprimir Cupom</a></li>
                </ul>