How to put a site search box in your blog?

In every blogspot.com blog, there should be a search box in the navbar at the top left corner of the page. Putting a search term in the box will lead to a page with all the posts containing that search term.However, some bloggers for various reasons like to hide or remove this navbar. You can replace this a Google sitesearch box like the one in the Header of this blog. However, to be able to do that, you have to have an AdSense account. If you want to apply for an AdSense account, you can click on the text link that reads "Generate revenue from your website. Google AdSense" at the top of the right sidebar. Also, this search box works in a different way from the search box in the navbar. It produces a page with links to posts that contain the search term.
There is one more way of putting a search box that gives the same result as the search box in the navbar, that is, producing a page that contains all posts rather than links. You can see an example of the search box at this blog: Custom Background. The search box is at the top of the right sidebar. Try typing in a search term (for example - Walpapers) into the box and click "Search" and observe what is the result. You will get a page of all the posts that contain the term "Walpapers" in it.

The method to do this is as follows. In the Layout, click on "Add a Search Box" then click "Save changes". The new Page Element will appear at the top of whichever section you have added the Page Element (in my case, it was in the right sidebar). Drag and drop to whatever position you want, preview if you want, then at the top right of the Layout, click "Save".