If you have too much unused space on your WordPress navigation bar (primary menu), you can fill it with Google Searchbar.
Login to your AdSense account and get a Google Search bar code.
In your WordPress Admin page, select Appearance->Edit
Select Header.php on the right.
Scroll down to the end of the file until you see a closing </nav> tag
Above it, add the following code:
<div class="newsearchform"> [put the Google code here] </div>
Now open styles.css and add the following
.newsearchform
{
margin:10px 10px 10px 0px;
float: right;
}
That’s it. Now you have the Google Custom Search in your navigation bar.