It's a common task that you need to check if your single checkbox 

is checked or not before doing something with that.

JSON is JavaScript Object Notation 

You may be required to select all <p> elements with specific class 

or other ways using jquery.

The jquery ajax() method is used to do AJAX (asynchronous HTTP) request. As we  know ajax is used to do things without loading the page. 

You can show wall posts of any public facebook page/group/profile
using Graph api in your website if you know javascript & jquery.

you may want to show smooth jquery popup when user visited
your site or on a button click in any page,etc... from code behind.

i am here sharing codes for showing popup using jquery properly -

jquery dialog is not only best for showing only content but
also can be used to show form,buttons for postback.......
but for this jquery dialog must be appended to form as -