You keep visiting sites and see that cool Google search boxes that let you either search your entire site or search the entire Google database, all without leaving your site's page! If you also want to have something like this, then I am sure you would have already got the Google Search Box for Adsense or have got the paid Google search box for your website.
The code works fine if your website has simple HTML or HTM pages. The moment you have master page (Which 99% of you would have in case your web site has been built using asp.net), the code provided by Google will throw an error if you place it on your master page. [More]