Eventually a component on a page is going to need to pull in some new information and you don't always want to reload the whole page. Making use of Ajax allows you to avoid a full reload but when you use Ajax with Sitecore there are a few important things to keep in mind: Make sure you set up your controller to function with the Ajax call. Are you sending back some data, the whole rendering, or are you just updating something internally? Be ready to handle whatever is coming into or out of the controller. Note that if the Ajax function is posting data you must add [HttpPost] before the controller method. Regardless of how you get to your controller - there won’t be Sitecore context! Your controller has no idea what the user was doing or where they were on your site when the Ajax call was made. You need to pass all the information in your model to the controller including the data item and anything else relevant for your controller to give context. One way to give context is ...