Open Visual Studio 2010 and create a Visual Web Part project as selecting from SharePoint 2010 tab
Now provide name of the site where you want to deploy the web part.
Click on Validate button to validate the site. If you are able to connect and get the following message then we are we are good to go.
Open VisualWebPart1UserControl.ascx and add the following script.
After adding above script add
Now add below script,
Inside script tag, write a function
And now you can see that in this function IntelliSense is working.
So in JavaScript the function would be working like below.