用javascript读取xml、DTD

get.xml
++++++++++++++++++++++++++++++++++++
<?xml version="1.0"?>
<!DOCTYPE note SYSTEM "note.dtd">
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>+++++++++++++++++++++++++++++++++++++++
note.dtd++++++++++++++++++++++++++++++++++++++
<!ELEMENT note (to,from,heading,body)>
<!ELEMENT to (#PCDATA)>
<!ELEMENT from (#PCDATA)>
<!ELEMENT heading (#PCDATA)>
<!ELEMENT body (#PCDATA)>+++++++++++++++++++++++++++++++++用javascript 把to\from\heading\body中的字符打印出来