$source = preg_replace( "#\[youtube=([^\]]+)\]#ies", "\$this->build_youtube('\\1')", $source );

$source = preg_replace( "#\[vk=([^\]]+)\]#ies", "\$this->build_vk('\\1')", $source );

$txt = preg_replace( "#<!--dle_youtube_begin:(.+?)-->(.+?)<!--dle_youtube_end-->#is", '[youtube=\\1]', $txt );

$txt = preg_replace( "#<!--dle_vk_begin:(.+?)-->(.+?)<!--dle_vk_end-->#is", '[vk=\\1]', $txt );

function build_url($url = array()) {

function build_vk($url) {
        $url = $this->clear_url( urldecode( $url ) );
        $url = str_replace("&amp;","&", $url );        
        if( $url == "" ) return;
        $source = @parse_url ( $url );
        $source['host'] = str_replace( "www.", "", strtolower($source['host']) );
        if ($source['host'] != "vk.com" AND $source['host'] != "vkontakte.ru") return "[vk=".$url."]";
        if ($source['host'] == "vk.com")
            return '<!--dle_vk_begin:'.$url.'--><center><iframe src=\"'.$url.'\" width=\"585\" height=\"360\" frameborder=\"0\"></iframe></center><!--dle_vk_end-->';
        else
            return '<!--dle_vk_begin:'.$url.'--><center><iframe src=\"'.$url.'\" width=\"585\" height=\"360\" frameborder=\"0\"></iframe></center><!--dle_vk_end-->';
    }

<script language="javascript" type="text/javascript">
/*<![CDATA[*/
document.onmouseup = function(){
var t =  document.getElementsByTagName('textarea');
for (var i=0; i<t.length; i++)  {
  t[i].value=t[i].value.replace(/<iframe src="(.*?)".*?<\/iframe>/gim, '[vk=$1]');
}
}
/*]]>*/
</script>

</body>

<script language="javascript" type="text/javascript">
/*<![CDATA[*/
document.onmouseup = function(){
    
    var t =  document.getElementsByTagName('textarea');
    var short_scrollTop = document.getElementById('short_story').scrollTop;
    var short_scrollLeft = document.getElementById('short_story').scrollLeft;
    var full_scrollTop = document.getElementById('full_story').scrollTop;
    var full_scrollLeft = document.getElementById('full_story').scrollLeft;

    for (var i=0; i<t.length; i++)  {
      t[i].value=t[i].value.replace(/<iframe src="(.*?)".*?<\/iframe>/gim, '[vk=$1]');
    }
    
    document.getElementById('short_story').scrollLeft = short_scrollLeft;
    document.getElementById('short_story').scrollTop = short_scrollTop;
    document.getElementById('full_story').scrollLeft = full_scrollLeft;
    document.getElementById('full_story').scrollTop = full_scrollTop;
}
/*]]>*/

</script>