An article about Google Map API V3 show a live demo that does not work. Where is the bug?

I was reading the nice article called Using PHP/MySQL with Google Maps

At the end of the article they provide a link to view a live demo开发者_JAVA技巧 but actually it does not work. It only displays the map but not the markers.

Does any one have an explanation about this bug and how to fix it.

Thanks in advance for your help.

Chrome throws up an error of "Uncaught TypeError: Cannot read property 'documentElement' of null".

The issue seems to stem from the AJAX call, in that the URL simply returns the PHP code, rather than the expected XML response. See here: http://gmaps-samples-v3.googlecode.com/svn/trunk/articles/phpsqlajax/phpsqlajax_genxml.php

Well the ajax request isn't working. In the source code it reads

   // Change this depending on the name of your PHP file
  downloadUrl("phpsqlajax_genxml.php", function(data) {

And hitting that php file with my browser just lists out the code. Looks like they expect you to implement that part yourself.

There is no demo the links are all to code. You will have to implement the code yourself. I have a demo based on this for railway stations in UK

It seems to be google's limit by hour/frequency, etc.

It happened to me randomly, i.e. what just worked no longer did and the other way around. (I was changing a value and re-testing every 10 seconds) Wait a few minutes and try again.