where can i find org.w3c.dom class

hi i am just wondering if anyone can tell me where i can get the package org.w3c.dom I have imported it but i am trying to use the org.w3c.dom.document class and in the class of org.w3c.dom that i have document is not part of it and i can't find out where to get it.
Thanks
Tex

I just went for the first time to w3c.org and found this.

It should be included in the jar file of your XML parser/processor. And you meant "Document" and not "document," right?