A search bar is necessary for a good website. Creating your own search engine from scratch might be a difficult task but this task can be skipped with the help of Google. Google has created a website to create a custom search bar, to create your own check the below link.
You have to create the search bar at the above website and for that please follow the article mentioned below:
To add a custom Google search engine in a Google site website, select embed option from the insert panel and then go to embed code division of the dialogue box appeared.
Write your code in the space provided. To add a Custom search engine code is: