Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <script src="loadxmldoc.js"> </script> </head> <body> <script> xmlDoc=loadXMLDoc("books.xml"); newNode=xmlDoc.createElement("book"); x=xmlDoc.documentElement; y=xmlDoc.getElementsByTagName("book"); document.write("Book elements before: " + y.length); document.write("<br>"); x.insertBefore(newNode,y[3]); y=xmlDoc.getElementsByTagName("book"); document.write("Book elements after: " + y.length); </script> </body> </html>
Result:
W3Schools.com - Try it yourself