Under Template->Page Elements tab, click “Add a Page Element” at the place where you want your search box to appear. Select “HTML/JavaScript”.
There are several HTML codes posted on the net. I tried a few, and found the one that works as
The HTML code to insert is this:-
Remember to change YOUR BLOG URL to the URL or web address of your Blog. Also, change the NAME OF YOUR BLOG to that which you want to call your site. For instance, if your Blog Name is long, you may want to write something like “Search Here” or “Search this site”.
You can also change the “Search” button to say, “Hit” or “Go”, by changing the Value.