Modern browsers have an enormous number of built-in functions, sometimes very handy These ones, having to do with tree handling, came up the other day : domParsing, nodeIteration and treeWalking The built in domParser function takes a tree in html/dom or xml format : <catalog>    <book id="bk101">       <author>Gambardella, Matthew</author>       <title>XML Developer''s Guide</title>       <genre>Computer</genre>       <price>44