encoding problem httpwebresponse

here dash formula :

httpwebrequest webrequest = (httpwebrequest)webrequest.create(request.rawurl);
webrequest.defaultwebproxy = null;//ensure loop going again proxy
httpwebresponse response = (httpwebresponse)webrequest.getresponse();
string charset = response.characterset;
encoding encoding;
if (string.isnullorempty(charset))
encoding = encoding.default;
else
encoding = encoding.getencoding(charset);

streamreader resstream = new streamreader(response.getresponsestream(), encoding);
return resstream.readtoend();

the problem i exam :

all "" displaying well. i have try change ascii utf8 still arrangement wrong. i have tested html record browser browser arrangement html calm good i am graceful certain problem slight i download html file.

what should i change?

removed passed imageshack link

update 1: formula exam record changed