XML文档设计一个DTD文档

<?xml version="1.0" encoding="gb2312"?>
<document>
<title> 顾客列表</title>
<customer ID=”20090101002”>
<username>王涛</username>
<password>123456</password>
<email>[email protected]</email>
<registerdate>200805</registerdate>
<address>
    <phone>12345678</phone>
<street>山东大学</street>
</address>
</customer>
</document>