screenshots.gif

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <input type="text"><br>
    <input type="text"><br>
    <input type="text"><br>
    <input type="text"><br>
    <input type="text"><br>
    <input type="text"><br>
    <input type="text"><br>


    <script>

        var tets = document.getElementsByTagName("input");

        for(var i = 0; i < tets.length; i++){


            tets[i].onfocus = function(){

                for(var j = 0; j < tets.length; j++){

                    tets[j].style.backgroundColor = "";

                }



               this.style.backgroundColor = "yellow";

            };

        };

    </script>
</body>
</html>