Window.open() method opens a new window . If we try to refresh the parent on change of something in the opened window , what are the ways to do it ? One possible way is to call reload(true) on the opener. It reloads the whole document for you.

When we send a request to the server , we expect a response. When we make an Ajax call to server with the help of XMLHttpRequest ,we have an option to get the response in many different formats. It can be a plain text , CSV(comma separated) , Xml etc. If the return data is in complex form or in a form of an object you need something called JSON. This post would give you a start up confidence to use JSON.