When processing xhtml, to obtain maximum compatibility, you need to send application/xhtml+xml to Firefox, Safari, Opera and other standards-compliant browsers, and send text/html to IE:
Program code
<%dim xm
if instr(request.servervariables("http_accept"), "application/xhtml+xml") > 0 or instr(request.servervariables("http_user_agent"), "w3c_validator") > 0 then
response.contenttype="application/xhtml+xml"
xm="<!doctype html public ""-//w3c//dtd xhtml 1.1//en"" "" http://www.w3.org/tr/xhtml11/dtd/xhtml11.dtd "">"
else
'http://qqface.downcodes.com/
response.contenttype="text/html"
xm="<!doctype html public ""-//w3c//dtd xhtml 1.0 strict//en"" "" http://www.w3.org/tr/xhtml1/dtd/xhtml1-strict.dtd "" >"
end if
%>
Test: Use IE to access the source code and you can see that the output is xhtml 1.0 strict. It is xhtml1.1 under ff or opera. It can pass the verification without changing it, but there will be a warning message.