function _getlinkportsymbol($port_id, $linktype)
 {
     $retval = '<span onclick=window.open("' . makeHrefProcess(portlist::urlparamsarray(array('op' => 'PortLinkDialog', 'port' => $port_id, 'linktype' => $linktype))) . '","name","height=800,width=800");' . '>';
     $img = getImageHREF('plug', $linktype . ' Link this port');
     if ($linktype == 'back') {
         $img = str_replace('<img', '<img style="transform:rotate(180deg);-o-transform:rotate(180deg);-ms-transform:rotate(180deg);-moz-transform:rotate(180deg);-webkit-transform:rotate(180deg);"', $img);
     }
     $retval .= $img;
     $retval .= "</span>";
     return $retval;
 }