PHP使用XSLT生成了Doctype问题

I am transforming XHTML to XHTML using XSLT and Doctype part is giving me problem

<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="LimeSurvey.xslt"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
...
</html>

and this is not valid xml, according to IE8, FF3. Is there any way to prevent generating DOCType, xmlns from php engine? Or is there any way to make XSLT ignore DOCTYPE and xmlns?

Thanks, Ebe

You'll need to insert the DOCTYPE in a CDATA block as seen here.

Ok, that was 7 years ago, so HTML 5 now:

<xsl:output doctype-public="html" />

gives the required html 5 output...