获取flashvars的正则表达式

我想从下面代码中的字符串中获得flashvars。但是在代码的末尾，匹配的值带有其他属性，如pluginspage。我该怎么修理它?我的正则表达式有问题吗?

下面是我的代码:

string source = "<embed src='"http://godtube.com/flvplayer.swf'" FlashVars='"videoThumb=http://www.godtube.com/thumb/1_30772.jpg&flvPath=http://www.godtube.com/flvideo1/47/30772.flv'" wmode='"transparent'" quality='"high'" width='"330'" height='"270'" name='"flv_demo'" align='"middle'" allowScriptAccess='"sameDomain'" type='"application/x-shockwave-flash'" pluginspage='"http://www.macromedia.com/go/getflashplayer'" /></embed>";
Regex sRgx = new Regex("flashvars='"(.*)'"", RegexOptions.Multiline);
Match regexMatch = sRgx.Match(source);
if (regexMatch.Success)
{
    string matched = regexMatch.Groups[1].Value;
}

Regex sRgx = new Regex("flashvars='"(.*?)'"", RegexOptions.Multiline);