Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <script src="loadxmldoc.js"> </script> </head> <body> <script> xmlDoc=loadXMLDoc("books.xml"); x=xmlDoc.getElementsByTagName("book"); for(i=0;i<x.length;i++) { attlist=x.item(i).attributes; att=attlist.getNamedItem("category"); att.value="BESTSELLER"; } //Output all attribute values for (i=0;i<x.length;i++) { document.write(x[i].getAttribute('category')); document.write("<br>"); } </script> </body> </html>
Result:
W3Schools.com - Try it yourself