if I understand you correctly you need to do it this way:
$showgallery .= '<a href="#" onclick="return hs.htmlExpand(this, { src: \''.$myplayer.'\', objectType: \'swf\', width: 560, objectWidth: 560, objectHeight: 280, maincontentText: \'You need to upgrade your Flash player\',swfOptions: { version: \'7\' ,params: {wmode: \transparent\'}, flashvars: { playOnStart: \'true\', MediaLink: \''.$vlink.'\'},} } )" class="highslide">link</a>';